欢迎您访问程序员文章站本站旨在为大家提供分享程序员计算机编程知识!
您现在的位置是: 首页  >  IT编程

java数据库操作类演示实例分享(java连接数据库)

程序员文章站 2024-02-13 09:52:04
复制代码 代码如下:package org.load.demo; import java.io.ioexception;import java.util.list;imp...

复制代码 代码如下:

package org.load.demo;

import java.io.ioexception;
import java.util.list;
import java.util.map;

import javax.servlet.servletexception;
import javax.servlet.http.httpservlet;
import javax.servlet.http.httpservletrequest;
import javax.servlet.http.httpservletresponse;

import com.loadphp.simple4j.contentvalues;
import com.loadphp.simple4j.db;
import com.loadphp.simple4j.utils;

public class myservlet extends httpservlet {

 @override
 protected void doget(httpservletrequest req, httpservletresponse resp)
   throws servletexception, ioexception {
  string action = req.getparameter("action");
  if("show".equalsignorecase(action)) {
   this.findall(req, resp);
  }else if("del".equalsignorecase(action)) {
   this.del(req, resp);
  }else if("edit".equalsignorecase(action)) {
   this.find(req, resp);
  }else if("update".equalsignorecase(action)) {
   this.update(req, resp);
  }else if("insert".equalsignorecase(action)) {
   this.insert(req, resp);
  }
 }

 @override
 protected void dopost(httpservletrequest req, httpservletresponse resp)
   throws servletexception, ioexception {
  this.doget(req, resp);
 }
 

 private void findall(final httpservletrequest req, httpservletresponse resp) {
//  db db = this.getdb();
//  list<map<string, object>> userlist = db.findall("*");  // 查询全部
//  db.close();
//  req.setattribute("userlist", userlist);
//  try {
//   req.getrequestdispatcher("/index.jsp").forward(req, resp);
//  } catch (servletexception e) {
//   e.printstacktrace();
//  } catch (ioexception e) {
//   e.printstacktrace();
//  }

  db db = this.getdb();
  db.findall(new db.queryallcallback() {
   public void callback(list<map<string, object>> list) {
    req.setattribute("userlist", list);
   }
  }, "*");

  try {
   req.getrequestdispatcher("/index.jsp").forward(req, resp);
  } catch (servletexception e) {
   e.printstacktrace();
  } catch (ioexception e) {
   e.printstacktrace();
  }
 }

 private void del(httpservletrequest req, httpservletresponse resp) {
  db db = this.getdb();
  db.where(new contentvalues().put("id", req.getparameter("id"))).del();
  db.close();
  this.findall(req, resp);
 }

 private void find(final httpservletrequest req, httpservletresponse resp) {
  db db = this.getdb();
//  map<string, object> map = db.where(new contentvalues().put("id", req.getparameter("id"))).find(
//    "id", "name", "birthday", "pwd");

  db.find(new db.querycallback() {
   public void callback(map<string, object> map) {
    req.setattribute("user", map);
   }
  }, "id","name","birthday");

  db.close();

  try {
   req.getrequestdispatcher("/edit.jsp").forward(req, resp);
  } catch (servletexception e) {
   e.printstacktrace();
  } catch (ioexception e) {
   e.printstacktrace();
  }
 }

 private void insert(httpservletrequest req, httpservletresponse resp) {
  db db = this.getdb();
  db.insert(utils.params2array(req, 3, "null","user","birth","pwd"));
  db.close();
  this.findall(req, resp);
 }

 private void update(httpservletrequest req, httpservletresponse resp) {
  db db = this.getdb();
  db.where(new contentvalues().put("id", req.getparameter("id"))).update(
    new contentvalues().put("name", req.getparameter("user"))
      .put("pwd", utils.md5(req.getparameter("pwd")))
      .put("birthday", req.getparameter("birth")));
  db.close();
  this.findall(req, resp);
 }

 private db getdb() {
//  db.driver = "com.mysql.jdbc.driver";               // driver
  db.uri = "jdbc:mysql://localhost:3306/forjava";    // uri
//  db.user = "root";                                  // mysql用户名
//  db.pwd = "";            // mysql密码
  db.connect("utf-8");          // 连接数据库并设置编码
  return db.init("users");         // 设置操作的表名,并返回数据库操作对象
 }
}