java数据库操作类演示实例分享(java连接数据库)
本文导语: 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.si...
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 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 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 map = db.where(new ContentValues().put("id", req.getParameter("id"))).find(
// "id", "name", "birthday", "pwd");
db.find(new DB.QueryCallback() {
public void callback(Map 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
}
}