用占位符和数组来操作数据库总是提示下角标越界，找了半天也没弄明白哪里有问题，这个地方是跟着云课堂老师的讲解做的，只不过操作的数据表不一样，但是老师那个就没问题，我就出了问题

，如果有大神能帮忙看看，真的感激不尽！！！！

下面是BaseDao数据库操作通用类

package basedao;

/*

* 数据库操作通用类

*/

import java.io.IOException;

import java.io.InputStream;

import java.sql.Connection;

import java.sql.DriverManager;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.sql.SQLException;

import java.sql.Statement;

import java.util.Properties;

public class BaseDao {

protected Connection conn;

protected PreparedStatement ps;

protected Statement stmt;

protected ResultSet rs;

//获取数据库连接

public boolean getConnection(){

String driverClass = null;

String jdbcUrl = null;

String user = null;

String password = null;

//读取类路径下的jdbc.properties文件

try {

InputStream is = getClass().getClassLoader().getResourceAsStream("jdbc.properties");

Properties properties = new Properties();

properties.load(is);

driverClass = properties.getProperty("driver");

jdbcUrl = properties.getProperty("jdbcUrl");

user = properties.getProperty("user");

password = properties.getProperty("password");

//加载驱动程序

Class.forName("oracle.jdbc.driver.OracleDriver");

conn = DriverManager.getConnection("jdbc:oracle:thin:@localhost:1521:shop","shop_display","1234");

} catch (ClassNotFoundException e) {

e.printStackTrace();

return false;

} catch (IOException e) {

e.printStackTrace();

} catch (SQLException e) {

e.printStackTrace();

return false;

}

return true;

}

//增删改

public int executeUpdate(String sql,Object ... params){

int updateRows = 0;

getConnection();

try {

ps=conn.prepareStatement(sql);

//填充占位符

for(int i = 0;i <= params.length;i++){

ps.setObject(i+1, params);

updateRows = ps.executeUpdate();

} catch (SQLException e) {

e.printStackTrace();

}

return updateRows;

}

//查询

public ResultSet executeSQL(String sql,Object[] params){

getConnection();

try {

ps=conn.prepareStatement(sql);

//填充占位符

for(int i = 0;i <= params.length;i++){

ps.setObject(i+1, params);     //就是数组这里，控制台抛出的异常里面提示下角标越界,这里我在eclipse上面没有写错：params后面是有字母i的，但是不知道为什么放到论坛上后面的总是消失，编辑好几次了，一直不显示

}

rs = ps.executeQuery();

} catch (SQLException e) {

e.printStackTrace();

}

return rs;

}

//关闭资源

public boolean closeResource (){

if(rs!=null){

try {

rs.close();

} catch (SQLException e) {

e.printStackTrace();

return false;

}

}

if(ps!=null){

try {

ps.close();

} catch (SQLException e) {

e.printStackTrace();

return false;

}

}

if(stmt!=null){

try {

stmt.close();

} catch (SQLException e) {

e.printStackTrace();

return false;

}

}

if(conn!=null){

try {

conn.close();

} catch (SQLException e) {

e.printStackTrace();

return false;

}

}

return true;

}

}

下面是DataBao接口

package data.impl;

public interface DataDao {

//添加数据

public void addData(int id, String name,int location,int leveis);

//删除数据

public void deleteData(int id);

//根据id修改数据

public void updateData(String name,int id);

//查询新闻信息

public void queryData();

}

下面是接口实现类

package data.impl;

import java.sql.ResultSet;

import java.sql.SQLException;

import basedao.BaseDao;

public class DataDaoImpl extends BaseDao implements DataDao{

//增加数据

public void addData(int id, String name,int location,int leveis){

try{

String sql = "insert into custom (id,name,location,leveis) VALUES (?,?,?,?)";

Object[] params={id,name,location,leveis};

int i = this.executeUpdate(sql,params);

if(i>0){

System.out.println("插入数据成功！");

}

}finally{

this.closeResource();

}

}

//删除数据

public void deleteData(int id){

try {

String sql = "delete from custom where id = ?";

Object[] params={id};

int i = this.executeUpdate(sql,params);

if(i>0){

System.out.println("删除数据成功！");

}

}finally{

this.closeResource();

}

}

//修改数据

public void updateData(String name,int id){

try {

String sql = "update custom set name = ? where id = ?";

Object[] params={name,id};

int i = this.executeUpdate(sql,params);

if(i>0){

System.out.println("更改数据成功！");

}

}finally{

this.closeResource();

}

}

//查询新闻信息

public void queryData(){

try {

String sql = "select * from custom";

Object[] params={ };

ResultSet rs=this.executeSQL(sql, params);

//(4)处理执行结果(ResultSet)，释放资源

try {

while(rs.next()){

int id = rs.getInt("id");

String name = rs.getString("name");

int location = rs.getInt("location");

int leveis = rs.getInt("leveis");

System.out.println(id + "\t" +name + "\t"+ location + "\t\t" + leveis);

}

} catch (SQLException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}finally{

this.closeResource();

}

}

public static void main(String[] args){

DataDaoImpl ddi = new DataDaoImpl();

//  ddi.addData(13,"华为",3,2);

//  ddi.deleteData(13);

//  ddi.updateData("万科",12);

ddi.queryData();

}

}

下面是数据库的表

上面黑体字加粗的部分eclipse里并没有写错

2016-5-3 19:36

2016-5-4 10:55

本帖最后由 遠山如黛 于 2016-5-4 10:55 编辑

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