ResultSet自动封装数据到实体对象

package com.ant.util; import java.lang.reflect.Method; import java.lang.reflect.Modifier; import java.sql.Connection; import java.sql.DriverManager; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.ResultSetMetaData; import java.sql.SQLException; import java.util.ArrayList; import java.util.Collection; import java.util.Iterator; public class AntResult { private Object[] beanMatch(Class clazz, String beanProperty) { Object[] result = new Object[2]; char beanPropertyChars[] = beanProperty.toCharArray(); beanPropertyChars[0] = Character.toUpperCase(beanPropertyChars[0]); String s = new String(beanPropertyChars); String names[] = { ("set" + s).intern(), ("get" + s).intern(), ("is" + s).intern(), ("write" + s).intern(), ("read" + s).intern() }; Method getter = null; Method setter = null; Method methods[] = clazz.getMethods(); for (int i = 0; i < methods.length; i++) { Method method = methods[i]; // 只取公共字段 if (!Modifier.isPublic(method.getModifiers())) continue; String methodName = method.getName().intern(); for (int j = 0; j < names.length; j++) { String name = names[j]; if (!name.equals(methodName)) continue; if (methodName.startsWith("set") || methodName.startsWith("read")) setter = method; else getter = method; } } result[0] = getter; result[1] = setter; return result; } private void beanRegister(Object object, String beanProperty, String value) { Object[] beanObject = beanMatch(object.getClass(), beanProperty); Object[] cache = new Object[1]; Method getter = (Method) beanObject[0]; Method setter = (Method) beanObject[1]; try { // 通过get获得方法类型 String methodType = getter.getReturnType().getName(); if (methodType.equalsIgnoreCase("long")) { cache[0] = new Long(value); setter.invoke(object, cache); } else if (methodType.equalsIgnoreCase("int") || methodType.equalsIgnoreCase("integer")) { cache[0] = new Integer(value); setter.invoke(object, cache); } else if (methodType.equalsIgnoreCase("short")) { cache[0] = new Short(value); setter.invoke(object, cache); } else if (methodType.equalsIgnoreCase("float")) { cache[0] = new Float(value); setter.invoke(object, cache); } else if (methodType.equalsIgnoreCase("double")) { cache[0] = new Double(value); setter.invoke(object, cache); } else if (methodType.equalsIgnoreCase("boolean")) { cache[0] = new Boolean(value); setter.invoke(object, cache); } else if (methodType.equalsIgnoreCase("java.lang.String")) { cache[0] = value; setter.invoke(object, cache); } else if (methodType.equalsIgnoreCase("java.io.InputStream")) { } else if (methodType.equalsIgnoreCase("char")) { cache[0] = (Character.valueOf(value.charAt(0))); setter.invoke(object, cache); } } catch (Exception e) { e.printStackTrace(); } } public Collection get(final Connection connection, final Class clazz, final String sql) { // 创建PreparedStatement PreparedStatement ptmt = null; // 创建resultset ResultSet rset = null; // 创建collection Collection collection = null; try { // 赋予实例 ptmt = connection.prepareStatement(sql); rset = ptmt.executeQuery(); collection = get(rset, clazz); } catch (SQLException e) { System.err.println(e.getMessage()); } finally { try { // 关闭rs并释放资源 if (rset != null) { rset.close(); rset = null; } // 关闭ps并释放资源 if (ptmt != null) { ptmt.close(); ptmt = null; } } catch (SQLException e) { System.err.println(e.getMessage()); } } return collection; } public Collection get(final ResultSet result, final Class clazz) { // 创建collection Collection collection = null; try { ResultSetMetaData rsmd = result.getMetaData(); // 获得数据列数 int cols = rsmd.getColumnCount(); // 创建等同数据列数的arraylist类型collection实例 collection = new ArrayList(cols); // 遍历结果集 while (result.next()) { // 创建对象 Object object = null; try { // 从class获得对象实体 object = clazz.newInstance(); } catch (Exception e) { } // 循环每条记录 for (int i = 1; i <= cols; i++) { beanRegister(object, rsmd.getColumnName(i), result .getString(i)); } // 将数据插入collection collection.add(object); } } catch (SQLException e) { System.err.println(e.getMessage()); } finally { } return collection; } //===========================================// public static void main(String[] args) { // 加载驱动 try { Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver"); } catch (ClassNotFoundException e) { e.printStackTrace(); } // 连接字符串 String url = "jdbc:sqlserver://localhost:1433;databaseName=test"; Connection connection = null; PreparedStatement ps = null; ResultSet rs = null; try { // 创建连接 connection = DriverManager.getConnection(url, "sa", "javalife"); AntResult test = new AntResult(); // Ltest是我测试用类，实际操作请注入相关对象，支持set，get，is，read，writer为前缀数据对，更多请继续添加。 Collection collection = test.get(connection, com.ant.po.UserInfo.class, "select * from userinfo"); for (Iterator it = collection.iterator(); it.hasNext();) { com.ant.po.UserInfoltest = (com.ant.po.UserInfo) it.next(); System.out.println(ltest.getUserid() + ":" + ltest.getUserName()); } } // SQL异常，用于抛出SQL语句处理中所引发的错误。 catch (SQLException e) { System.err.println(e.getMessage()); } // finally，此标识用以包含必须访问的内容。 finally { try { // 关闭connection并释放资源 if (connection != null) { connection.close(); connection = null; } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } // 如果关闭时产生异常将由此抛出 } } } //需要注意的是 类中的属性要和 数据库的列名保持一致。再想一个问题，struts 的 FormBean 是 //不是用这个原理封装的数据啊。 今天很累了，改天把这个类在封装下，配合以前做的通用分页前台 //通用存储过程分页取得数据集后台，做个 jar 包 只需要传递一个类，在前台页面通过 el 表达 //式进行 //数据的展示和分页功能的实现。 这个程序真是越做越简单！ 

//UserInfo.java 实体类 package com.ant.entity; public class UserInfo { private int userID; private String userName; private String userPass; public int getUserID() { return userID; } public void setUserID(int userID) { this.userID = userID; } public String getUserName() { return userName; } public void setUserName(String userName) { this.userName = userName; } public String getUserPass() { return userPass; } public void setUserPass(String userPass) { this.userPass = userPass; } } 

本文转自：http://blog.sina.com.cn/s/blog_59d6717c0100eji3.html