更新MySQL数据库( java.sql.SQLException: No value specified for parameter 1) 异常 解决方法

package com.swift;

import java.io.File;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.List;

import com.google.gson.Gson;

public class UpdateUrl {

public static void main(String[] args) {

File file = new File("D:\\java_date", "questionJson.json");
String jsonResult = GetData.getData(file);
Gson gson = new Gson();
Root root = gson.fromJson(jsonResult, Root.class);
List<Result> result = root.getResult();
updateUrl(result);
}

private static void updateUrl(List<Result> result) {

Connection conn = DBUtil.getConn();
PreparedStatement ps = null;
try {

ps = conn.prepareStatement("update sw_question set url = ? where id=?)");
for (int i = 0; i < result.size(); i++) {
String str=result.get(i).getUrl();
int id=result.get(i).getId();
if (str != null && str.length() > 0) {
ps.setString(1, str.substring(str.lastIndexOf("/")+1));//图片的URL地址截图成图片名称后更新数据库
ps.setInt(2, id);
}
ps.executeUpdate();
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
DBUtil.closeAll(conn, ps, null);
}
}
}

package com.swift;

import java.io.File;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.util.List;

import com.google.gson.Gson;

public class UpdateUrl {

public static void main(String[] args) {

File file = new File("D:\\java_date", "questionJson.json");
String jsonResult = GetData.getData(file);
Gson gson = new Gson();
Root root = gson.fromJson(jsonResult, Root.class);
List<Result> result = root.getResult();
updateUrl(result);
}

private static void updateUrl(List<Result> result) {

Connection conn = DBUtil.getConn();
PreparedStatement ps = null;
try {

ps = conn.prepareStatement("update sw_question set url = ? where id=?");
for (int i = 0; i < result.size(); i++) {
String str=result.get(i).getUrl();
System.out.println(str);
int id=result.get(i).getId();
if (str != null && str.length() > 0) {
int number=str.lastIndexOf("/")+1;
System.out.println(number);
String change=str.substring(number);
System.out.println(change);
ps.setString(1, change);
ps.setInt(2, id);
ps.addBatch();
}
}
ps.executeBatch();
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
DBUtil.closeAll(conn, ps, null);
}
}
}