JDBC增删改查和查唯一的完整代码解析

第一部分代码（实体类）

package com.wf.entity;
public class hehe{
private int hehe_id;
private string hehe_name;
private string hehe_gender;
public int gethehe_id(){
return hehe_id;
}
public void sethehe_id(int heheid){
hehe_id=heheid;
}
public string gethehe_name() {
return hehe_name;
}
public void sethehe_name(string hehename) {
hehe_name = hehename;
}
public string gethehe_gender() {
return hehe_gender;
}
public void sethehe_gender(string hehegender) {
hehe_gender = hehegender;
}
}

第二部分 basedao（增删改查和查唯一）

package com.wf.dao;
import java.sql.connection;
import java.sql.drivermanager;
import java.sql.preparedstatement;
import java.sql.resultset;
import java.sql.sqlexception;
public class basedao{
protected static final string driver="com.mysql.jdbc.driver";
protected static final string url="mysql://localhost:3306/mysql";
protected static final string user="root";
protected static final string password="******";
protected connection connection=null;
protected preparedstatement preparedstatement=null;
protected resultset resultset =null;
protected void getconnection() throws classnotfoundexception, sqlexception{
  class.forname(driver);
  this.connection =drivermanager.getconnection (url,user,password);
}
/**
* 通用的增删改方法
* @param sql sql语句
* @param params 参数数组
* @return 受影响的行数
*/
protected int executeupdate(string sql ,string[]params){
int result=-1;
try {
this.getconnection();
this.preparedstatement=this.connection.preparestatement(sql);
if(null!=params){
for (int i = 0; i < params.length; i++) {
this.preparedstatement.setstring(i+1, params[i]);
} 
}
result= this.preparedstatement.executeupdate();
} catch (classnotfoundexception e) {
e.printstacktrace();
} catch (sqlexception e) {
e.printstacktrace();
}finally{
this.close();
}
return result;
}
/**
* 查询结果集的方法
* @param sql
* @param params
*/
protected void executequery(string sql,string[]params){
try {
this.getconnection();
this.preparedstatement=this.connection.preparestatement(sql);
if(null!=params){
for (int i = 0; i < params.length; i++) {
this.preparedstatement.setstring(i+1, params[i]);
} 
}
this.resultset=this.preparedstatement.executequery();
} catch (classnotfoundexception e) {
e.printstacktrace();
} catch (sqlexception e) {
e.printstacktrace();
}
}

/**
* 查询唯一的结果
* @return object
*/
protected object executequeryunique(string sql,string[]params){
object object=null;
try {
this.getconnection();
this.preparedstatement=this.connection.preparestatement(sql);
if(null!=params){
for (int i = 0; i < params.length; i++) {
this.preparedstatement.setstring(i+1, params[i]);
} 
} 
this.resultset=this.preparedstatement.executequery();
if(this.resultset.next())
object=this.resultset.getobject(1);
} catch (classnotfoundexception e) {
e.printstacktrace();
} catch (sqlexception e) {
e.printstacktrace();
}
return object;
}
protected void close(){
try {
if(null!=this.resultset)
this.resultset.close();
if(null!=this.preparedstatement)
this.preparedstatement.close();
if(null!=this.connection)
this.connection.close();
} catch (sqlexception e) {
e.printstacktrace();
}
}

第三部分 hehedao

package com.wf.dao;
import java.sql.connection;
import java.sql.preparedstatement;
import java.sql.sqlexception;
import com.wf.entity.hehe;
public class hehedao extends basedao{
public boolean insert(hehe hehe){
string sql="insert into hehe(hehe_name,hehe_gender) values(?,?)" ;
string []params=new string[]{hehe.gethehe_name(),hehe.gethehe_gender()};
return this.executeupdate(sql, params)>0? true:false;
}

第四部分 测试test_basedao_insert

package com.wf.test;
import com.wf.dao.hehedao;
import com.wf.entity.hehe;
public class test_basedao_insert {
public static void main(string[] args) {
hehe hehe=new hehe();
hehe.sethehe_name("个");
hehe.sethehe_gender("b");
hehedao _hd=new hehedao();
if(_hd.insert(hehe))
system.out.println("成功!");
else
system.out.println("失败!");
}
}