SQL语句写在JavaBean(UserBean.java)中 sql 一般是不写在javabean里面的 应该写在专门的数据库访问类里面
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然后 jsp 可以调用这个 dao 得到数据显示在页面上
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jsp
大致就这样
public void query(String sql) {
try {
stm = conn.createStatement();
rs = stm.executeQuery(sql);
} catch (Exception e) {
}
}
这个方法,但是这个方法很怪,你应该在这个方法里把resultSet遍历,装进javaBean中,通过set方法,然后返回List<javaBean>,public List<javaBean> query(String sql) {
try {
stm = conn.createStatement();
rs = stm.executeQuery(sql);
while(rs.hasNext()){
Bean b = new Bean();
b.setName(rs.getString("name"));
..........//这种格式
}
} catch (Exception e) {
}
}
private String nation_name;
public int getNation_id() {
return nation_id;
}
public void setNation_id(int nation_id) {
this.nation_id = nation_id;
}
public String getNation_name() {
return nation_name;
}
public void setNation_name(String nation_name) {
this.nation_name = nation_name;
}
public nationBean() {
super();
}
}
dao:
package com.dao;import com.beans.nationBean;public class nationdDao { public boolean insert (nationBean nb){
int i=-1;
String sql="insert into nation values("+nb.getNation_id()+",'"+nb.getNation_name()+"')";
return update(sql);
}
}
private Integer nation_id;
private String nation_name;
public Integer getNation_id() {
return nation_id;
}
public void setNation_id(Integer nation_id) {
this.nation_id = nation_id;
}
public String getNation_name() {
return nation_name;
}
public void setNation_name(String nation_name) {
this.nation_name = nation_name;
}
}Util Java code
class JdbcUtil {
private static final ThreadLocal<Connection> tl=new ThreadLocal<Connection>(); public static Connection getConnection() throws Exception{
Connection conn=tl.get();
if(conn==null){
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
String url = "jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=employee)";
String name = "sa";
String password = "";
conn = DriverManager.getConnection(url,name,password);
tl.set(conn);
return conn ;
}
return conn ;
} public static void release(Connection conn,Statement stm,ResultSet rs){
if(rs!=null) try{ rs.close(); } catch(Exception ae){}
if(stm!=null) try{ stm.close(); } catch(Exception ae){}
if(conn!=null) try{ conn.close(); } catch(Exception ae){}
}
}
DAO Java code
class NationDAO{
public List<Nation> queryNation(){
List l = null;
Nation nation = null;
Connection conn = null ;
Statement stm = null ;
ResultSet rs = null ;
try{
conn = JdbcUtil.getConnection();
stm = conn.createStatement();
String sql = "select nation_id,nation_name from nation" ;
rs = stm.executeQuery(sql);
while(rs.next()){
nation = new Nation();
nation.setNation_id(rs.getInt(1));
nation.setNation_name(rs.getString(2));
l.add(nation);
}
return l;
}catch(Exception e){
}
finally{
JdbcUtil.release(conn, stm, rs);
}
}
}