Java自动生成mybatis更新sql语句

package com.hebrf.test.sql;

import java.awt.Desktop;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;

public class CreUpSql {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub

String[] noUpKeys = {"BH"};
String[][] contions = {{"BH","BH ="} };
new CreUpSql().createUpdateSql("tableName", noUpKeys,contions);
}

/**
*  生成更新sql语句
* @param tableName 表名
* @param noUpKeys 不被更新的字段
* @param contions where条件  [0]条件值的键  【1】条件名字的键+条件标志  如：  like =  等
*/
public void createUpdateSql(String tableName,String[] noUpKeys,String[][] contions) {
String fileName = "D:" + File.separator + "sqlwork" + File.separator
+ tableName + "UPDATE" + ".txt";

String[][] strs = getFieldsNames(tableName);

checkArrNull(strs);

File f = createNewFile(fileName);

createUpFile(f,strs,noUpKeys,tableName,contions);
}

/**
* 检查str有没有在数组values中
* 检查不通过的话返回ture
* @return
*/
public boolean check(String str,String[] values){
boolean flag = false;
for(int i = 0; i < values.length; i++){
if(str.equals(values[i])){
flag = true;
break;
}
}
return flag;
}

/**
* 添加修改sql文件内容
* @param f
* @param strs
* @param tableName
*/
private void createUpFile(File f, String[][] strs,String[] noUpKeys, String tableName,String[][] contions) {

OutputStream out;
try {
out = new FileOutputStream(f, true);

String str = " UPDATE " + tableName + " ";
writeStrToFile(out,f,str);

writeStrToFile(out,f,"<set>");
// *******************添加SET***************************************************************************
for (int i = 0; i < strs.length; i++) {
if(noUpKeys!=null){
if(check(strs[i][0],noUpKeys)){
continue;
}
}
String temp = "#{" + strs[i][0] + "}";
if (strs[i][1].startsWith("DATE")
|| strs[i][1].startsWith("TIME")) {
temp = "to_date(" + temp + ",'yyyy-mm-dd hh24:mi:ss')";
}
String nullstr = strs[i][0]+"=null";
if (i == (strs.length - 1)) {
} else {
temp += ",";
nullstr += ",";
}
temp = "<when test=\" " + strs[i][0] + "!=null  \">" + strs[i][0]+"="+temp + "</when>";
//upNullFlag默认为空    （全部更新）  upNullFlag如果为false 则不更新VO中为空的值
temp = temp+"<when test=\" " + strs[i][0] + "==null and  upNullFlag=='true' \">" + nullstr + "</when>";
temp = "\t<choose>" + temp +"</choose>";

writeStrToFile(out,f,temp);
}
writeStrToFile(out,f,"</set>");
if(contions!=null && contions.length > 0){
creatWhere(out, f,contions);
}
out.close();
System.out.println(tableName + "修改语句生成成功-->" + f.toString());
Desktop.getDesktop().open(f);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}

}

/**
*
* @param out
* @param f
* @param contions [0]条件值的键  【1】条件名字的键+条件标志  如：  like =  等
*/
private void creatWhere(OutputStream out, File f, String[][] contions) {
// TODO Auto-generated method stub
writeStrToFile(out,f,"<where>");

for(int i=0; i < contions.length; i++){
String temp = "\tand "+contions[i][1]+" #{"+contions[i][0]+"}";
writeStrToFile(out,f,temp);
}
writeStrToFile(out,f,"</where>");
}

/**
* 将字符串写到指定文件中
* @param out
* @param f
* @param str
*/
private void writeStrToFile(OutputStream out, File f, String str) {
// TODO Auto-generated method stub
byte[] b = ("\r\n\t\t"+str).getBytes();
for (int i = 0; i < b.length; i++) {
try {
out.write(b[i]);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
return;
}
}
}

/**
* 检查数组是否为空
* @param strs
*/
private void checkArrNull(String[][] strs) {
if (strs == null || strs.length == 0) {
try {
throw new Exception("不存在的表名");
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
return;
}
}
}

/**
* 根据文件名称创建一个新文件并返回
* @param fileName
* @return
*/
public File createNewFile(String fileName) {
File f = new File(fileName);

try {
if (f.exists()) { // 如果文件存在则删除
f.delete();
}
f.createNewFile();// 创建sql文件
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
return f;
}

/**
* 获取表的所有字段名称
*
* @param tabname
* @return
*/
public String[][] getFieldsNames(String tabname) {

Connection conn = ConnUtil.getConn();
Statement stat = null;
ResultSet rs = null;
ResultSetMetaData data = null; // 定义ResultSetMetaData对象
String[][] resultStrs = null;
int coloumCount = 0;
try {
stat = conn.createStatement();
String sql = "select * from " + tabname;
rs = stat.executeQuery(sql);// 查询数据
data = rs.getMetaData();
coloumCount = data.getColumnCount();
resultStrs = new String[coloumCount][2];
for (int i = 0; i < coloumCount; i++) {
resultStrs[i][0] = data.getColumnName(i + 1);
resultStrs[i][1] = data.getColumnTypeName(i + 1);
}

// 关闭数据库资源
if (rs != null) {
rs.close();
}
if (conn != null) {
conn.close();
}
} catch (SQLException e) {
e.printStackTrace();
}
return resultStrs;
}
}