练习题——Gson解析、利用JDBC连接数据库进行数据的存取及查询等的综合

/**
*对数据的查询类
*/
package com.liuzhonglin.exercise;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
//3.在另外一个类当中读取数据库的结果。
//规则：用户输入id，就能得到关于这个id的产品名和产品信息。
//    可以循环输入，如果用户输入exit，就退出查询系统。
public class ExerciseDemo01 {
public static void main(String[] args) {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
try {
Class.forName("org.sqlite.JDBC");
Connection conn = DriverManager.getConnection("jdbc:sqlite:/"+"e:/test.db");
Statement stmt = conn.createStatement();

while(true){
System.out.println("请输入id：");
String str = br.readLine();
if(str.equals("exit")){
System.out.println("退出系统");
stmt.close();
conn.close();
return;
}
String sql = "select * from aa where id="+str;
ResultSet rs = stmt.executeQuery(sql);
while(rs.next()){
System.out.println("产品编号:"+str+",产品名称："+rs.getString("company")+"\n产品详情："+rs.getString("summary")+"\n");
}
}
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
}

<pre name="code" class="java">package com.liuzhonglin.exercise;
//http://218.244.149.129:9010/api/recommend.php
//
//1.通过接口获取网络数据，并解析
//2.把解析之后的结果当中的属性：id   company  summary  作为表当中的一条存入到数据库当中。
//3.在另外一个类当中读取数据库的结果。
//    规则：用户输入id，就能得到关于这个id的产品名和产品信息。
//	      可以循环输入，如果用户输入exit，就退出查询系统。
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;
import java.util.List;

import com.google.gson.Gson;

public class ExerciseDemo {
public static void main(String[] args) {
//解析数据
String path = "http://218.244.149.129:9010/api/recommend.php";
String str = HttpUtils.getByStringokHttp(path);
Data data = new Gson().fromJson(str, Data.class);
System.out.println(data);
//利用JDBC访问数据库，将解析出来的数据存入到数据库中
try {
Class.forName("org.sqlite.JDBC");
Connection conn = DriverManager.getConnection("jdbc:sqlite:/" + "e:/test.db");
Statement stmt = conn.createStatement();
String sql = "create table if not exists aa(id integer,company String,summary String)";
stmt.executeUpdate(sql);
String sql1 = "insert into aa(id,company,summary) values (?,?,?)";
PreparedStatement ps = conn.prepareStatement(sql1);
ps.executeUpdate();
List<Company> list = data.getRecommend();
for (Company c : list) {
ps.setInt(1, c.getId());
ps.setString(2, c.getCompany());
ps.setString(3, c.getSummary());
ps.executeUpdate();
}
//将数据存入数据库中的第二种方法
// int count=data.getRecommend().size();
// for (int i = 0; i < count; i++) {
// ps.setInt(1,data.getRecommend().get(i).getId());
// ps.setString(2, data.getRecommend().get(i).getCompany());
// ps.setString(3, data.getRecommend().get(i).getSummary());
// ps.executeUpdate();
// }
//在网数据库中存数据时候不用ResultSet，ResultSet结果集一般在从数据库中读取数据的时候用
// ResultSet rs = stmt.executeQuery(sql1);
// while(rs.next()){
// }
stmt.close();
conn.close();
ps.close();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
}
}
}

/*
* 工具类
*/
package com.liuzhonglin.exercise;

import java.io.IOException;

import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class HttpUtils {
public static String getByStringokHttp(String path){
String result = null;
OkHttpClient client = new OkHttpClient();
Request request = new Request.Builder().url(path).get().build();
try {
Response response = client.newCall(request).execute();
if(response.isSuccessful()){
result = response.body().string();
}
} catch (IOException e) {
e.printStackTrace();
}
return result;
}
}

/*
* Bean类
*/
package com.liuzhonglin.exercise;

public class Company {
private int id;
private String company;
private String summary;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getCompany() {
return company;
}
public void setCompany(String company) {
this.company = company;
}
public String getSummary() {
return summary;
}
public void setSummary(String summary) {
this.summary = summary;
}
public Company(int id, String company, String summary) {
super();
this.id = id;
this.company = company;
this.summary = summary;
}
public Company() {
super();
// TODO Auto-generated constructor stub
}
@Override
public String toString() {
return "Company [id=" + id + ", company=" + company + ", summary=" + summary + "]";
}
}

package com.liuzhonglin.exercise;

import java.util.List;

public class Data {
List<Company>recommend;

public List<Company> getRecommend() {
return recommend;
}

public void setRecommend(List<Company> recommend) {
this.recommend = recommend;
}

@Override
public String toString() {
return "Data [recommend=" + recommend + "]";
}

}