30个类手写Spring核心原理之自定义ORM（下）（7）

本文节选自《Spring 5核心原理》

3 基于Spring JDBC实现关键功能

3.1 ClassMappings

ClassMappings主要定义基础的映射类型，代码如下：

package com.tom.orm.framework;import java.lang.reflect.Field;import java.lang.reflect.Method;import java.lang.reflect.Modifier;import java.math.BigDecimal;import java.sql.Date;import java.sql.Timestamp;import java.util.Arrays;import java.util.HashMap;import java.util.HashSet;import java.util.Map;import java.util.Set;public class ClassMappings {private ClassMappings(){}static final Set<Class<?>> SUPPORTED_SQL_OBJECTS = new HashSet<Class<?>>();static {//只要这里写了，默认支持自动类型转换Class<?>[] classes = {boolean.class, Boolean.class,short.class, Short.class,int.class, Integer.class,long.class, Long.class,float.class, Float.class,double.class, Double.class,String.class,Date.class,Timestamp.class,BigDecimal.class};SUPPORTED_SQL_OBJECTS.addAll(Arrays.asList(classes));}static boolean isSupportedSQLObject(Class<?> clazz) {return clazz.isEnum() || SUPPORTED_SQL_OBJECTS.contains(clazz);}public static Map<String, Method> findPublicGetters(Class<?> clazz) {Map<String, Method> map = new HashMap<String, Method>();Method[] methods = clazz.getMethods();for (Method method : methods) {if (Modifier.isStatic(method.getModifiers()))continue;if (method.getParameterTypes().length != 0)continue;if (method.getName().equals("getClass"))continue;Class<?> returnType = method.getReturnType();if (void.class.equals(returnType))continue;if(!isSupportedSQLObject(returnType)){continue;}if ((returnType.equals(boolean.class)|| returnType.equals(Boolean.class))&& method.getName().startsWith("is")&& method.getName().length() > 2) {map.put(getGetterName(method), method);continue;}if ( ! method.getName().startsWith("get"))continue;if (method.getName().length() < 4)continue;map.put(getGetterName(method), method);}return map;}public static Field[] findFields(Class<?> clazz){return clazz.getDeclaredFields();}public static Map<String, Method> findPublicSetters(Class<?> clazz) {Map<String, Method> map = new HashMap<String, Method>();Method[] methods = clazz.getMethods();for (Method method : methods) {if (Modifier.isStatic(method.getModifiers()))continue;if ( ! void.class.equals(method.getReturnType()))continue;if (method.getParameterTypes().length != 1)continue;if ( ! method.getName().startsWith("set"))continue;if (method.getName().length() < 4)continue;if(!isSupportedSQLObject(method.getParameterTypes()[0])){continue;}map.put(getSetterName(method), method);}return map;}public static String getGetterName(Method getter) {String name = getter.getName();if (name.startsWith("is"))name = name.substring(2);elsename = name.substring(3);return Character.toLowerCase(name.charAt(0)) + name.substring(1);}private static String getSetterName(Method setter) {String name = setter.getName().substring(3);return Character.toLowerCase(name.charAt(0)) + name.substring(1);}}

3.2 EntityOperation

EntityOperation主要实现数据库表结构和对象类结构的映射关系，代码如下：

package com.tom.orm.framework;import java.lang.reflect.Field;import java.lang.reflect.Method;import java.sql.ResultSet;import java.sql.ResultSetMetaData;import java.sql.SQLException;import java.util.HashMap;import java.util.Map;import java.util.TreeMap;import javax.persistence.Column;import javax.persistence.Entity;import javax.persistence.Id;import javax.persistence.Table;import javax.persistence.Transient;import org.apache.log4j.Logger;import org.springframework.jdbc.core.RowMapper;import javax.core.common.utils.StringUtils;/*** 实体对象的反射操作** @param <T>*/public class EntityOperation<T> {private Logger log = Logger.getLogger(EntityOperation.class);public Class<T> entityClass = null; // 泛型实体Class对象public final Map<String, PropertyMapping> mappings;public final RowMapper<T> rowMapper;public final String tableName;public String allColumn = "*";public Field pkField;public EntityOperation(Class<T> clazz,String pk) throws Exception{if(!clazz.isAnnotationPresent(Entity.class)){throw new Exception("在" + clazz.getName() + "中没有找到Entity注解，不能做ORM映射");}this.entityClass = clazz;Table table = entityClass.getAnnotation(Table.class);if (table != null) {this.tableName = table.name();} else {this.tableName =  entityClass.getSimpleName();}Map<String, Method> getters = ClassMappings.findPublicGetters(entityClass);Map<String, Method> setters = ClassMappings.findPublicSetters(entityClass);Field[] fields = ClassMappings.findFields(entityClass);fillPkFieldAndAllColumn(pk,fields);this.mappings = getPropertyMappings(getters, setters, fields);this.allColumn = this.mappings.keySet().toString().replace("[", "").replace("]",""). replaceAll(" ","");this.rowMapper = createRowMapper();}Map<String, PropertyMapping> getPropertyMappings(Map<String, Method> getters, Map<String, Method> setters, Field[] fields) {Map<String, PropertyMapping> mappings = new HashMap<String, PropertyMapping>();String name;for (Field field : fields) {if (field.isAnnotationPresent(Transient.class))continue;name = field.getName();if(name.startsWith("is")){name = name.substring(2);}name = Character.toLowerCase(name.charAt(0)) + name.substring(1);Method setter = setters.get(name);Method getter = getters.get(name);if (setter == null || getter == null){continue;}Column column = field.getAnnotation(Column.class);if (column == null) {mappings.put(field.getName(), new PropertyMapping(getter, setter, field));} else {mappings.put(column.name(), new PropertyMapping(getter, setter, field));}}return mappings;}RowMapper<T> createRowMapper() {return new RowMapper<T>() {public T mapRow(ResultSet rs, int rowNum) throws SQLException {try {T t = entityClass.newInstance();ResultSetMetaData meta = rs.getMetaData();int columns = meta.getColumnCount();String columnName;for (int i = 1; i <= columns; i++) {Object value = rs.getObject(i);columnName = meta.getColumnName(i);fillBeanFieldValue(t,columnName,value);}return t;}catch (Exception e) {throw new RuntimeException(e);}}};}protected void fillBeanFieldValue(T t, String columnName, Object value) {if (value != null) {PropertyMapping pm = mappings.get(columnName);if (pm != null) {try {pm.set(t, value);} catch (Exception e) {e.printStackTrace();}}}}private void fillPkFieldAndAllColumn(String pk, Field[] fields) {//设定主键try {if(!StringUtils.isEmpty(pk)){pkField = entityClass.getDeclaredField(pk);pkField.setAccessible(true);}} catch (Exception e) {log.debug("没找到主键列，主键列名必须与属性名相同");}for (int i = 0 ; i < fields.length ;i ++) {Field f = fields[i];if(StringUtils.isEmpty(pk)){Id id = f.getAnnotation(Id.class);if(id != null){pkField = f;break;}}}}public T parse(ResultSet rs) {T t = null;if (null == rs) {return null;}Object value = null;try {t = (T) entityClass.newInstance();for (String columnName : mappings.keySet()) {try {value = rs.getObject(columnName);} catch (Exception e) {e.printStackTrace();}fillBeanFieldValue(t,columnName,value);}} catch (Exception ex) {ex.printStackTrace();}return t;}public Map<String, Object> parse(T t) {Map<String, Object> _map = new TreeMap<String, Object>();try {for (String columnName : mappings.keySet()) {Object value = mappings.get(columnName).getter.invoke(t);if (value == null)continue;_map.put(columnName, value);}} catch (Exception e) {e.printStackTrace();}return _map;}public void println(T t) {try {for (String columnName : mappings.keySet()) {Object value = mappings.get(columnName).getter.invoke(t);if (value == null)continue;System.out.println(columnName + " = " + value);}} catch (Exception e) {e.printStackTrace();}}}class PropertyMapping {final boolean insertable;final boolean updatable;final String columnName;final boolean id;final Method getter;final Method setter;final Class enumClass;final String fieldName;public PropertyMapping(Method getter, Method setter, Field field) {this.getter = getter;this.setter = setter;this.enumClass = getter.getReturnType().isEnum() ? getter.getReturnType() : null;Column column = field.getAnnotation(Column.class);this.insertable = column == null || column.insertable();this.updatable = column == null || column.updatable();this.columnName = column == null ? ClassMappings.getGetterName(getter) : ("".equals(column.name()) ? ClassMappings.getGetterName(getter) : column.name());this.id = field.isAnnotationPresent(Id.class);this.fieldName = field.getName();}@SuppressWarnings("unchecked")Object get(Object target) throws Exception {Object r = getter.invoke(target);return enumClass == null ? r : Enum.valueOf(enumClass, (String) r);}@SuppressWarnings("unchecked")void set(Object target, Object value) throws Exception {if (enumClass != null && value != null) {value = Enum.valueOf(enumClass, (String) value);}//BeanUtils.setProperty(target, fieldName, value);try {if(value != null){setter.invoke(target, setter.getParameterTypes()[0].cast(value));}} catch (Exception e) {e.printStackTrace();/*** 出错原因如果是boolean字段、mysql字段类型，设置tinyint(1)*/System.err.println(fieldName + "--" + value);}}}

3.3 QueryRuleSqlBuilder

QueryRuleSqlBuilder根据用户构建好的QueryRule来自动生成SQL语句，代码如下：

package com.tom.orm.framework;import java.util.ArrayList;import java.util.HashMap;import java.util.List;import java.util.Map;import java.util.regex.Matcher;import java.util.regex.Pattern;import org.apache.commons.lang.ArrayUtils;import com.tom.orm.framework.QueryRule.Rule;import javax.core.common.utils.StringUtils;/*** 根据QueryRule自动构建SQL语句*/public class QueryRuleSqlBuilder {private int CURR_INDEX = 0; //记录参数所在的位置private List<String> properties; //保存列名列表private List<Object> values; //保存参数值列表private List<Order> orders; //保存排序规则列表private String whereSql = "";private String orderSql = "";private Object [] valueArr = new Object[]{};private Map<Object,Object> valueMap = new HashMap<Object,Object>();/*** 获得查询条件* @return*/public String getWhereSql(){return this.whereSql;}/*** 获得排序条件* @return*/public String getOrderSql(){return this.orderSql;}/*** 获得参数值列表* @return*/public Object [] getValues(){return this.valueArr;}/*** 获取参数列表* @return*/public Map<Object,Object> getValueMap(){return this.valueMap;}/*** 创建SQL构造器* @param queryRule*/public  QueryRuleSqlBuilder(QueryRule queryRule) {CURR_INDEX = 0;properties = new ArrayList<String>();values = new ArrayList<Object>();orders = new ArrayList<Order>();for (QueryRule.Rule rule : queryRule.getRuleList()) {switch (rule.getType()) {case QueryRule.BETWEEN:processBetween(rule);break;case QueryRule.EQ:processEqual(rule);break;case QueryRule.LIKE:processLike(rule);break;case QueryRule.NOTEQ:processNotEqual(rule);break;case QueryRule.GT:processGreaterThen(rule);break;case QueryRule.GE:processGreaterEqual(rule);break;case QueryRule.LT:processLessThen(rule);break;case QueryRule.LE:processLessEqual(rule);break;case QueryRule.IN:processIN(rule);break;case QueryRule.NOTIN:processNotIN(rule);break;case QueryRule.ISNULL:processIsNull(rule);break;case QueryRule.ISNOTNULL:processIsNotNull(rule);break;case QueryRule.ISEMPTY:processIsEmpty(rule);break;case QueryRule.ISNOTEMPTY:processIsNotEmpty(rule);break;case QueryRule.ASC_ORDER:processOrder(rule);break;case QueryRule.DESC_ORDER:processOrder(rule);break;default:throw new IllegalArgumentException("type " + rule.getType() + " not supported.");}}//拼装where语句appendWhereSql();//拼装排序语句appendOrderSql();//拼装参数值appendValues();}/*** 去掉order** @param sql* @return*/protected String removeOrders(String sql) {Pattern p = Pattern.compile("order\\\\s*by[\\\\w|\\\\W|\\\\s|\\\\S]*", Pattern.CASE_INSENSITIVE);Matcher m = p.matcher(sql);StringBuffer sb = new StringBuffer();while (m.find()) {m.appendReplacement(sb, "");}m.appendTail(sb);return sb.toString();}/*** 去掉select** @param sql* @return*/protected String removeSelect(String sql) {if(sql.toLowerCase().matches("from\\\\s+")){int beginPos = sql.toLowerCase().indexOf("from");return sql.substring(beginPos);}else{return sql;}}/*** 处理like* @param rule*/private  void processLike(QueryRule.Rule rule) {if (ArrayUtils.isEmpty(rule.getValues())) {return;}Object obj = rule.getValues()[0];if (obj != null) {String value = obj.toString();if (!StringUtils.isEmpty(value)) {value = value.replace(\'*\', \'%\');obj = value;}}add(rule.getAndOr(),rule.getPropertyName(),"like","%"+rule.getValues()[0]+"%");}/*** 处理between* @param rule*/private  void processBetween(QueryRule.Rule rule) {if ((ArrayUtils.isEmpty(rule.getValues()))|| (rule.getValues().length < 2)) {return;}add(rule.getAndOr(),rule.getPropertyName(),"","between",rule.getValues()[0],"and");add(0,"","","",rule.getValues()[1],"");}/*** 处理 =* @param rule*/private  void processEqual(QueryRule.Rule rule) {if (ArrayUtils.isEmpty(rule.getValues())) {return;}add(rule.getAndOr(),rule.getPropertyName(),"=",rule.getValues()[0]);}/*** 处理 <>* @param rule*/private  void processNotEqual(QueryRule.Rule rule) {if (ArrayUtils.isEmpty(rule.getValues())) {return;}add(rule.getAndOr(),rule.getPropertyName(),"<>",rule.getValues()[0]);}/*** 处理 >* @param rule*/private  void processGreaterThen(QueryRule.Rule rule) {if (ArrayUtils.isEmpty(rule.getValues())) {return;}add(rule.getAndOr(),rule.getPropertyName(),">",rule.getValues()[0]);}/*** 处理>=* @param rule*/private  void processGreaterEqual(QueryRule.Rule rule) {if (ArrayUtils.isEmpty(rule.getValues())) {return;}add(rule.getAndOr(),rule.getPropertyName(),">=",rule.getValues()[0]);}/*** 处理<* @param rule*/private  void processLessThen(QueryRule.Rule rule) {if (ArrayUtils.isEmpty(rule.getValues())) {return;}add(rule.getAndOr(),rule.getPropertyName(),"<",rule.getValues()[0]);}/*** 处理<=* @param rule*/private  void processLessEqual(QueryRule.Rule rule) {if (ArrayUtils.isEmpty(rule.getValues())) {return;}add(rule.getAndOr(),rule.getPropertyName(),"<=",rule.getValues()[0]);}/*** 处理  is null* @param rule*/private  void processIsNull(QueryRule.Rule rule) {add(rule.getAndOr(),rule.getPropertyName(),"is null",null);}/*** 处理 is not null* @param rule*/private  void processIsNotNull(QueryRule.Rule rule) {add(rule.getAndOr(),rule.getPropertyName(),"is not null",null);}/*** 处理  <>\'\'* @param rule*/private  void processIsNotEmpty(QueryRule.Rule rule) {add(rule.getAndOr(),rule.getPropertyName(),"<>","\'\'");}/*** 处理 =\'\'* @param rule*/private  void processIsEmpty(QueryRule.Rule rule) {add(rule.getAndOr(),rule.getPropertyName(),"=","\'\'");}/*** 处理in和not in* @param rule* @param name*/private void inAndNotIn(QueryRule.Rule rule,String name){if (ArrayUtils.isEmpty(rule.getValues())) {return;}if ((rule.getValues().length == 1) && (rule.getValues()[0] != null)&& (rule.getValues()[0] instanceof List)) {List<Object> list = (List) rule.getValues()[0];if ((list != null) && (list.size() > 0)){for (int i = 0; i < list.size(); i++) {if(i == 0 && i == list.size() - 1){add(rule.getAndOr(),rule.getPropertyName(),"",name + " (",list.get(i),")");}else if(i == 0 && i < list.size() - 1){add(rule.getAndOr(),rule.getPropertyName(),"",name + " (",list.get(i),"");}if(i > 0 && i < list.size() - 1){add(0,"",",","",list.get(i),"");}if(i == list.size() - 1 && i != 0){add(0,"",",","",list.get(i),")");}}}} else {Object[] list =  rule.getValues();for (int i = 0; i < list.length; i++) {if(i == 0 && i == list.length - 1){add(rule.getAndOr(),rule.getPropertyName(),"",name + " (",list[i],")");}else if(i == 0 && i < list.length - 1){add(rule.getAndOr(),rule.getPropertyName(),"",name + " (",list[i],"");}if(i > 0 && i < list.length - 1){add(0,"",",","",list[i],"");}if(i == list.length - 1 && i != 0){add(0,"",",","",list[i],")");}}}}/*** 处理 not in* @param rule*/private void processNotIN(QueryRule.Rule rule){inAndNotIn(rule,"not in");}/*** 处理 in* @param rule*/private  void processIN(QueryRule.Rule rule) {inAndNotIn(rule,"in");}/*** 处理 order by* @param rule 查询规则*/private void processOrder(Rule rule) {switch (rule.getType()) {case QueryRule.ASC_ORDER://propertyName非空if (!StringUtils.isEmpty(rule.getPropertyName())) {orders.add(Order.asc(rule.getPropertyName()));}break;case QueryRule.DESC_ORDER://propertyName非空if (!StringUtils.isEmpty(rule.getPropertyName())) {orders.add(Order.desc(rule.getPropertyName()));}break;default:break;}}/*** 加入SQL查询规则队列* @param andOr and 或者 or* @param key 列名* @param split 列名与值之间的间隔* @param value 值*/private  void add(int andOr,String key,String split ,Object value){add(andOr,key,split,"",value,"");}/*** 加入SQL查询规则队列* @param andOr and 或则 or* @param key 列名* @param split 列名与值之间的间隔* @param prefix 值前缀* @param value 值* @param suffix 值后缀*/private void add(int andOr,String key,String split,String prefix,Object value,String suffix){String andOrStr = (0 == andOr ? "" :(QueryRule.AND == andOr ? " and " : " or "));properties.add(CURR_INDEX, andOrStr + key + " " + split + prefix + (null != value ? " ? " : " ") + suffix);if(null != value){values.add(CURR_INDEX,value);CURR_INDEX ++;}}/*** 拼装 where 语句*/private void appendWhereSql(){StringBuffer whereSql = new StringBuffer();for (String p : properties) {whereSql.append(p);}this.whereSql = removeSelect(removeOrders(whereSql.toString()));}/*** 拼装排序语句*/private void appendOrderSql(){StringBuffer orderSql = new StringBuffer();for (int i = 0 ; i < orders.size(); i ++) {if(i > 0 && i < orders.size()){orderSql.append(",");}orderSql.append(orders.get(i).toString());}this.orderSql = removeSelect(removeOrders(orderSql.toString()));}/*** 拼装参数值*/private void appendValues(){Object [] val = new Object[values.size()];for (int i = 0; i < values.size(); i ++) {val[i] = values.get(i);valueMap.put(i, values.get(i));}this.valueArr = val;}}

3.4 BaseDaoSupport

BaseDaoSupport主要是对JdbcTemplate的包装，下面讲一下其重要代码，请“小伙伴们” 关注『 Tom弹架构』可下载全部源代码。先看全局定义：

package com.tom.orm.framework;.../*** BaseDao 扩展类，主要功能是支持自动拼装SQL语句，必须继承方可使用* @author Tom*/public abstract class BaseDaoSupport<T extends Serializable, PK extends Serializable> implements BaseDao<T,PK> {private Logger log = Logger.getLogger(BaseDaoSupport.class);private String tableName = "";private JdbcTemplate jdbcTemplateWrite;private JdbcTemplate jdbcTemplateReadOnly;private DataSource dataSourceReadOnly;private DataSource dataSourceWrite;private EntityOperation<T> op;@SuppressWarnings("unchecked")protected BaseDaoSupport(){try{Class<T> entityClass = GenericsUtils.getSuperClassGenricType(getClass(), 0);op = new EntityOperation<T>(entityClass,this.getPKColumn());this.setTableName(op.tableName);}catch(Exception e){e.printStackTrace();}}protected String getTableName() { return tableName; }protected DataSource getDataSourceReadOnly() { return dataSourceReadOnly;  }protected DataSource getDataSourceWrite() { return dataSourceWrite;  }/*** 动态切换表名*/protected void setTableName(String tableName) {if(StringUtils.isEmpty(tableName)){this.tableName = op.tableName;}else{this.tableName = tableName;}}protected void setDataSourceWrite(DataSource dataSourceWrite) {this.dataSourceWrite = dataSourceWrite;jdbcTemplateWrite = new JdbcTemplate(dataSourceWrite);}protected void setDataSourceReadOnly(DataSource dataSourceReadOnly) {this.dataSourceReadOnly = dataSourceReadOnly;jdbcTemplateReadOnly = new JdbcTemplate(dataSourceReadOnly);}private JdbcTemplate jdbcTemplateReadOnly() {return this.jdbcTemplateReadOnly;}private JdbcTemplate jdbcTemplateWrite() {return this.jdbcTemplateWrite;}/*** 还原默认表名*/protected void restoreTableName(){ this.setTableName(op.tableName);  }/*** 获取主键列名称，建议子类重写* @return*/protected abstract String getPKColumn();protected abstract void setDataSource(DataSource dataSource);//此处有省略}

为了照顾程序员的一般使用习惯，查询方法的前缀命名主要有select、get、load，兼顾Hibernate和MyBatis的命名风格。

/*** 查询函数，使用查询规则* 例如以下代码查询条件为匹配的数据** @param queryRule 查询规则* @return 查询的结果List*/public List<T> select(QueryRule queryRule) throws Exception{QueryRuleSqlBuilder bulider = new QueryRuleSqlBuilder(queryRule);String ws = removeFirstAnd(bulider.getWhereSql());String whereSql = ("".equals(ws) ? ws : (" where " + ws));String sql = "select " + op.allColumn + " from " + getTableName() + whereSql;Object [] values = bulider.getValues();String orderSql = bulider.getOrderSql();orderSql = (StringUtils.isEmpty(orderSql) ? " " : (" order by " + orderSql));sql += orderSql;log.debug(sql);return (List<T>) this.jdbcTemplateReadOnly().query(sql, this.op.rowMapper, values);}.../*** 根据SQL语句执行查询，参数为Object数组对象* @param sql 查询语句* @param args 为Object数组* @return 符合条件的所有对象*/public List<Map<String,Object>> selectBySql(String sql,Object... args) throws Exception{return this.jdbcTemplateReadOnly().queryForList(sql,args);}.../*** 分页查询函数，使用查询规则<br>* 例如以下代码查询条件为匹配的数据** @param queryRule 查询规则* @param pageNo 页号，从1开始* @param pageSize 每页的记录条数* @return 查询的结果Page*/public Page<T> select(QueryRule queryRule,final int pageNo, final int pageSize) throws Exception{QueryRuleSqlBuilder bulider = new QueryRuleSqlBuilder(queryRule);Object [] values = bulider.getValues();String ws = removeFirstAnd(bulider.getWhereSql());String whereSql = ("".equals(ws) ? ws : (" where " + ws));String countSql = "select count(1) from " + getTableName() + whereSql;long count = (Long) this.jdbcTemplateReadOnly().queryForMap(countSql, values).get ("count(1)");if (count == 0) {return new Page<T>();}long start = (pageNo - 1) * pageSize;//在有数据的情况下，继续查询String orderSql = bulider.getOrderSql();orderSql = (StringUtils.isEmpty(orderSql) ? " " : (" order by " + orderSql));String sql = "select " + op.allColumn +" from " + getTableName() + whereSql + orderSql + " limit " + start + "," + pageSize;List<T> list = (List<T>) this.jdbcTemplateReadOnly().query(sql, this.op.rowMapper, values);log.debug(sql);return new Page<T>(start, count, pageSize, list);}.../*** 分页查询特殊SQL语句* @param sql 语句* @param param  查询条件* @param pageNo   页码* @param pageSize 每页内容* @return*/public Page<Map<String,Object>> selectBySqlToPage(String sql, Object [] param, final int pageNo, final int pageSize) throws Exception {String countSql = "select count(1) from (" + sql + ") a";long count = (Long) this.jdbcTemplateReadOnly().queryForMap(countSql,param).get("count(1)");if (count == 0) {return new Page<Map<String,Object>>();}long start = (pageNo - 1) * pageSize;sql = sql + " limit " + start + "," + pageSize;List<Map<String,Object>> list = (List<Map<String,Object>>) this.jdbcTemplateReadOnly(). queryForList(sql, param);log.debug(sql);return new Page<Map<String,Object>>(start, count, pageSize, list);}/*** 获取默认的实例对象* @param <T>* @param pkValue* @param rowMapper* @return*/private <T> T doLoad(Object pkValue, RowMapper<T> rowMapper){Object obj = this.doLoad(getTableName(), getPKColumn(), pkValue, rowMapper);if(obj != null){return (T)obj;}return null;}

插入方法，均以insert开头：

/*** 插入并返回ID* @param entity* @return*/public PK insertAndReturnId(T entity) throws Exception{return (PK)this.doInsertRuturnKey(parse(entity));}/*** 插入一条记录* @param entity* @return*/public boolean insert(T entity) throws Exception{return this.doInsert(parse(entity));}/*** 批量保存对象.<br>** @param list 待保存的对象List* @throws InvocationTargetException* @throws IllegalArgumentException* @throws IllegalAccessException*/public int insertAll(List<T> list) throws Exception {int count = 0 ,len = list.size(),step = 50000;Map<String, PropertyMapping> pm = op.mappings;int maxPage = (len % step == 0) ? (len / step) : (len / step + 1);for (int i = 1; i <= maxPage; i ++) {Page<T> page = pagination(list, i, step);String sql = "insert into " + getTableName() + "(" + op.allColumn + ") values ";// (" + valstr.toString() + ")";StringBuffer valstr = new StringBuffer();Object[] values = new Object[pm.size() * page.getRows().size()];for (int j = 0; j < page.getRows().size(); j ++) {if(j > 0 && j < page.getRows().size()){ valstr.append(","); }valstr.append("(");int k = 0;for (PropertyMapping p : pm.values()) {values[(j * pm.size()) + k] = p.getter.invoke(page.getRows().get(j));if(k > 0 && k < pm.size()){ valstr.append(","); }valstr.append("?");k ++;}valstr.append(")");}int result = jdbcTemplateWrite().update(sql + valstr.toString(), values);count += result;}return count;}private Serializable doInsertRuturnKey(Map<String,Object> params){final List<Object> values = new ArrayList<Object>();final String sql = makeSimpleInsertSql(getTableName(),params,values);KeyHolder keyHolder = new GeneratedKeyHolder();final JdbcTemplate jdbcTemplate = new JdbcTemplate(getDataSourceWrite());try {jdbcTemplate.update(new PreparedStatementCreator() {public PreparedStatement createPreparedStatement(Connection con) throws SQLException {PreparedStatement ps = con.prepareStatement(sql,Statement.RETURN_GENERATED_KEYS);for (int i = 0; i < values.size(); i++) {ps.setObject(i+1, values.get(i)==null?null:values.get(i));}return ps;}}, keyHolder);} catch (DataAccessException e) {log.error("error",e);}if (keyHolder == null) { return ""; }Map<String, Object> keys = keyHolder.getKeys();if (keys == null || keys.size() == 0 || keys.values().size() == 0) {return "";}Object key = keys.values().toArray()[0];if (key == null || !(key instanceof Serializable)) {return "";}if (key instanceof Number) {//Long k = (Long) key;Class clazz = key.getClass();//       return clazz.cast(key);return (clazz == int.class || clazz == Integer.class) ? ((Number) key).intValue() : ((Number)key).longValue();} else if (key instanceof String) {return (String) key;} else {return (Serializable) key;}}/*** 插入* @param params* @return*/private boolean doInsert(Map<String, Object> params) {String sql = this.makeSimpleInsertSql(this.getTableName(), params);int ret = this.jdbcTemplateWrite().update(sql, params.values().toArray());return ret > 0;}

删除方法，均以delete开头：

/*** 删除对象.<br>** @param entity 待删除的实体对象*/public boolean delete(T entity) throws Exception {return this.doDelete(op.pkField.get(entity)) > 0;}/*** 删除对象.<br>** @param list 待删除的实体对象列表* @throws InvocationTargetException* @throws IllegalArgumentException* @throws IllegalAccessException*/public int deleteAll(List<T> list) throws Exception {String pkName = op.pkField.getName();int count = 0 ,len = list.size(),step = 1000;Map<String, PropertyMapping> pm = op.mappings;int maxPage = (len % step == 0) ? (len / step) : (len / step + 1);for (int i = 1; i <= maxPage; i ++) {StringBuffer valstr = new StringBuffer();Page<T> page = pagination(list, i, step);Object[] values = new Object[page.getRows().size()];for (int j = 0; j < page.getRows().size(); j ++) {if(j > 0 && j < page.getRows().size()){ valstr.append(","); }values[j] = pm.get(pkName).getter.invoke(page.getRows().get(j));valstr.append("?");}String sql = "delete from " + getTableName() + " where " + pkName + " in (" + valstr.toString() + ")";int result = jdbcTemplateWrite().update(sql, values);count += result;}return count;}/*** 根据id删除对象。如果有记录则删之，没有记录也不报异常<br>* 例如：删除主键唯一的记录** @param id 序列化id*/protected void deleteByPK(PK id)  throws Exception {this.doDelete(id);}/*** 删除实例对象，返回删除记录数* @param tableName* @param pkName* @param pkValue* @return*/private int doDelete(String tableName, String pkName, Object pkValue) {StringBuffer sb = new StringBuffer();sb.append("delete from ").append(tableName).append(" where ").append(pkName).append(" = ?");int ret = this.jdbcTemplateWrite().update(sb.toString(), pkValue);return ret;}

修改方法，均以update开头：

/*** 更新对象.<br>** @param entity 待更新对象* @throws IllegalAccessException* @throws IllegalArgumentException*/public boolean update(T entity) throws Exception {return this.doUpdate(op.pkField.get(entity), parse(entity)) > 0;}/*** 更新实例对象，返回删除记录数* @param pkValue* @param params* @return*/private int doUpdate(Object pkValue, Map<String, Object> params){String sql = this.makeDefaultSimpleUpdateSql(pkValue, params);params.put(this.getPKColumn(), pkValue);int ret = this.jdbcTemplateWrite().update(sql, params.values().toArray());return ret;}

至此一个完整的ORM框架就横空出世。当然，还有很多优化的地方，请小伙伴可以继续完善。