java 中list集合遍历数据库内容 关于bean 的 sat get方法

首先建立一个bean：

public class Stu

{
private int id;
private String name;
private int age;
private String Email;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getEmail() {
return Email;
}
public void setEmail(String email) {
Email = email;
}

}

建立数据库连接：

package com.conn.util;


import java.sql.Connection;
import java.sql.DriverManager;


public class ConnectionUtil {
public static Connection getconn() {
try {
Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection(
"jdbc:mysql://localhost:3306/test", "root", "111");
return conn;
} catch (Exception e) {
return null;
}
}


}

得到数据库内容：

public class DaoIMPL {
public List listquery() {
Connection conn = ConnectionUtil.getconn();
Statement st = null;
ResultSet rs = null;
try {
st = conn.createStatement();
rs = st.executeQuery("SELECT * FROM stu");
List list = new ArrayList();
while (rs.next()) {
Stu s = new Stu();
String name = rs.getString("name");
int age = rs.getInt("age");
String Email = rs.getString("Email");
System.out.print(name);
System.out.print(age);
System.out.println(Email);
s.setAge(age);
s.setEmail(Email);
s.setName(name);
list.add(s);


}
return list;
} catch (Exception e) {
// TODO: handle exception
System.out.println("添加失败");
return null;
} finally {
try {
rs.close();
st.close();
conn.close();
} catch (Exception e2) {
// TODO: handle exception
}
}
}

遍历list集合的内容：

第一种：

使用for循环：

public static void main(String[] args) {
DaoIMPL d=new DaoIMPL();
List list = d.listquery();
for(int i=0;i Stu s=(Stu) list.get(i);

System.out.println(s.getName());

System.out.println(s.getAge());

System.out.println(s.getEmail());

}

}

第二种添加泛型：

public class DaoIMPL{

public List listquery() {
Connection conn = ConnectionUtil.getconn();
Statement st = null;
ResultSet rs = null;
try {
st = conn.createStatement();
rs = st.executeQuery("SELECT * FROM stu");
ArrayList list = new ArrayList();
while (rs.next()) {
Stu s = new Stu();
String name = rs.getString("name");
int age = rs.getInt("age");
String Email = rs.getString("Email");
System.out.print(name);
System.out.print(age);
System.out.println(Email);
s.setAge(age);
s.setEmail(Email);
s.setName(name);
list.add(s);


}
return list;
} catch (Exception e) {
// TODO: handle exception
System.out.println("添加失败");
return null;
} finally {
try {
rs.close();
st.close();
conn.close();
} catch (Exception e2) {
// TODO: handle exception
}
}

}

//输出：

public static void main(String[] args) {
DaoIMPL d=new DaoIMPL();
List list = d.listquery();
for(Stu s:list){

System.out.println(s.getName());

System.out.println(s.getAge());

System.out.println(s.getEmail());

}
}

当然还有一种就是Tterator 迭代器 ！