java 脚本处理sql脚本文件，生成指定文件格式（数据结构，IO流等知识）

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;

/**
*
* 功能：
* 处理*.sql文件
* 需求：
* 修改所有varchar字段的的长度
* 原长度小于等于10，则加10处理
* 原长度大于10，则*2处理
* 目标：
* 生成符合数据库语法的后缀名位.sql的文本文件
*
* @author [email protected]
*
*/
public class UpdateSqlFile {

public static void main(String[] args) throws Exception {

BufferedReader br = new BufferedReader(new FileReader("d:\\sql\\test01.sql"));
BufferedWriter bw = new BufferedWriter(new FileWriter("d:\\sql\\test02.sql"));

ArrayList list = new ArrayList();
Map> tableEntry = new HashMap>();
Map map = null;

String line = null;
StringBuffer strb = null;
String tableName = null;
String cloumn = null;
int len = 0;

while((line = br.readLine()) != null){
if(line.contains("CREATE TABLE") && !line.contains("--")){
strb = new StringBuffer(line + "\r\n");
} else if(!line.contains(";") && strb != null && !line.contains("--")){
if(strb != null){
strb.append(line + "\r\n");
}
}else if(line.contains(":") && strb != null){
strb.append(line+"\r\b");
list.add(strb.toString());
strb = null;
}
}

for (int i = 0; i < list.size(); i++) {
tableName = list.get(i).substring(list.get(i).indexOf("CREATE TABLE"), list.get(i).indexOf("("))
.replaceAll(" ", "").replaceAll("\"", "");
String[] info = list.get(i).split("\r\n");
map = new HashMap();

for (int j = 0; j < info.length; j++) {
info[0] = info[0].substring(info[0].indexOf("("));
if(info[j].contains("VARCHAR") && info[j].contains("(") && info[j].contains(")")){

cloumn = info[j].substring(info[j].indexOf("\"") + 1, info[j].lastIndexOf("\""));
len = Integer.parseInt(info[j].substring(info[j].lastIndexOf("("), info[j].indexOf(")")));

map.put(cloumn, len);
}
}
tableEntry.put(tableName, map);
}

String str = null;
for (Map.Entry> entryTable : tableEntry.entrySet()) {
for (Map.Entry entry : entryTable.getValue().entrySet()) {
int temp;
if(entry.getValue() <= 10){
temp = entry.getValue() + 10;
}else{
temp = entry.getValue() * 2;
}
str = "alter table " + entryTable.getKey() + " alter " + entry.getKey() + "set data type varchar(" + temp + ");";

bw.write(str);
bw.newLine();
bw.flush();
}
}
bw.close();
br.close();
}
}

转载于:https://www.cnblogs.com/cl-andy/p/9908888.html