package com.wzh.jdbc;

import java.lang.reflect.Field;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.ResultSetMetaData;

import java.sql.SQLException;

import java.util.ArrayList;

import java.util.Iterator;

import java.util.List;

public class JDBCTemplate<T> {

public boolean save(final T t) {

String simpleName = t.getClass().getSimpleName();

System.out.println("simpleName" + simpleName);

final StringBuffer sql = new StringBuffer();

final Field[] fields = t.getClass().getDeclaredFields();

sql.append("insert into tb_").append(simpleName).append("(")

.append(fields[0].getName());

for (int i = 1; i < fields.length; i++) {

sql.append(",").append(fields[i].getName());

}

sql.append(") values(?");

for (int i = 1; i < fields.length; i++) {

sql.append(",?");

}

sql.append(")");

System.out.println("SQL - >" + sql.toString());

return template(new Callback<Boolean>() {

@Override

public Boolean doInCallback(Connection conn,

PreparedStatement pstm, ResultSet rs) throws Throwable {

pstm = conn.prepareStatement(sql.toString());

int index = 1;

for (Field field : fields) {

if (!field.getName().equals("UserId")) {

if (!field.isAccessible())

field.setAccessible(true);

//取得字段的值

System.out.println("field get --> "+field.get(t));

pstm.setObject(index, field.get(t));

index++;

}

}

int row = pstm.executeUpdate();

return row != 0 ? true : false;

}

});

}

public boolean delete(Class clazz, final int id) {

String simpleName = clazz.getSimpleName();

System.out.println("simpleName" + simpleName);

final String sql = "delete from tb_" + simpleName + " where id=?";

System.out.println("SQL->" + sql);

return template(new Callback<Boolean>() {

@Override

public Boolean doInCallback(Connection conn,

PreparedStatement pstm, ResultSet rs) throws Throwable {

pstm = conn.prepareStatement(sql);

pstm.setObject(1, id);

int row = pstm.executeUpdate();

return row != 0 ? true : false;

}

});

}

public List<T> findAll(final Class clazz) {

String simpleName = clazz.getSimpleName();

System.out.println("simpleName->" + simpleName);

final StringBuffer sql = new StringBuffer();

// 构建SQL语句 select [所有字段] from tb_class.getName() where id=?

Field[] fields = clazz.getDeclaredFields();

sql.append("select ").append(fields[0].getName());

for (int i = 1; i < fields.length; i++) {

sql.append(",").append(fields[i].getName());

}

sql.append(" from tb_").append(simpleName);

System.out.println("SQL - >" + sql.toString());

return template(new Callback<List<T>>() {

@Override

public List<T> doInCallback(Connection conn,

PreparedStatement pstm, ResultSet rs) throws Throwable {

pstm = conn.prepareStatement(sql.toString());

rs = pstm.executeQuery();

// 返回集合对象

List list = new ArrayList();

ResultSetMetaData rsmd = rs.getMetaData();

int count = rsmd.getColumnCount();

while (rs.next()) {

Object object = clazz.newInstance();

// 要得到rs返回的所有字段和信息

for (int i = 1; i <= count; i++) {

// 循环拿到列名id

String column = rsmd.getColumnName(i);

Field f = clazz.getDeclaredField(column);

if (!f.isAccessible()) {

f.setAccessible(true);

}

f.set(object, rs.getObject(column));

}

list.add(object);

}

return list;

}

});

}

private Connection conn = null;

public JDBCTemplate() {

super();

conn = ConnectionFactory.GetConnection();

}

protected interface Callback<E> {

E doInCallback(Connection conn, PreparedStatement pstm, ResultSet rs)

throws Throwable;

}

protected <E> E template(Callback<E> callback) throws DataAccessException {

PreparedStatement pstm = null;

ResultSet rs = null;

try {

return callback.doInCallback(conn, pstm, rs);

} catch (Throwable e) {

throw new DataAccessException(e);

} finally {

ConnectionFactory.Close(pstm, rs);

}

}

/**

* 开启事务

* */

public void beginTransaction() {

try {

conn.setAutoCommit(false);

} catch (SQLException e) {

e.printStackTrace();

}

}

/**

* 提交事务

* */

public void commit() {

try {

conn.commit();

} catch (SQLException e) {

e.printStackTrace();

}

}

/**

* 回滚事务

* */

public void rollback() {

try {

conn.rollback();

} catch (SQLException e) {

e.printStackTrace();

}

}

/**

* 关闭连接

* */

public void close() {

try {

conn.close();

} catch (SQLException e) {

e.printStackTrace();

}

}

}