文件结构目录：
package com.tool;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import java.util.List;
public class FileIOUtil
{
/**
* tablename.properties文件路径
*/
private static String pathName= System.getProperty("user.dir").replace("\\", "/") +"/config/";
/**
* tableName文件
*/
private File tableFile = null;
//配置文件中保存表名的最大个数
/*HS_ConfigInfo hs_ConfigInfo = HS_ConfigInfo.getInstance();
private int maxTableNameNum = Integer.parseInt(HS_ConfigInfo.getDataSaveTimes().trim());*/
HS_ConfigInfo hs_ConfigInfo = null;
private int maxTableNameNum = 0;
public static void main(String[] args)
{
List<String> a = new ArrayList<String>();
a.add("r_e_mp_read_14_03_01");
a.add("r_e_mp_read_14_03_03");
a.add("r_e_mp_read_14_03_05");
a.add("r_e_mp_read_14_03_02");
a.add("r_e_mp_read_14_03_06");
a.add("r_e_mp_read_14_03_04");
a.add("r_e_mp_read_14_03_08");
a.add("r_e_mp_read_14_03_07");
try
{
//删除一个表名
//fileIOUtil.tableNameDel(a.get(2));
//增加一个表名
//fileIOUtil.tableNameAdd(a.get(3));
FileIOUtil fileIOUtil = new FileIOUtil("r_e_mp_day_demand_tablename");
fileIOUtil.writeFile(a);
System.out.println(fileIOUtil.tableNameList().toString());
}
catch (IOException e)
{
e.printStackTrace();
}
catch (Exception e)
{
e.printStackTrace();
}
}
//构造函数
public FileIOUtil(String filename) throws IOException
{
filename = pathName+ filename +".properties";
tableFile = new File(filename);
hs_ConfigInfo = HS_ConfigInfo.getInstance();
maxTableNameNum = Integer.parseInt(hs_ConfigInfo.getDataSaveTimes().trim());
filename = null;
}
//从文件中读取数据
public List<String> readFile() throws IOException{
FileInputStream inputStream = null;
InputStreamReader inputStreamReader = null;
BufferedReader bufReader = null;
ArrayList<String> tableNameList = new ArrayList<String>();
try
{
inputStream = new FileInputStream(tableFile);
inputStreamReader = new InputStreamReader(inputStream);
bufReader = new BufferedReader(inputStreamReader);
String str = null;
//循环按行读取文件中的内容
while((str= bufReader.readLine()) != null){
if(str.trim().length()>0){
tableNameList.add(str);
}
str = null;
}
//对结果集降序排列后返回
return sortStr(tableNameList);
}
catch (FileNotFoundException e)
{
throw e;
}
catch (IOException e)
{
throw e;
}finally{
try
{
if(inputStream != null){
inputStream.close();
inputStream = null;
}
if(inputStreamReader != null){
inputStreamReader.close();
inputStreamReader = null;
}
if(bufReader != null){
bufReader.close();
bufReader = null;
}
}
catch (IOException e)
{
throw e;
}
}
}
//往文件中写入数据
public boolean writeFile(List<String> tableNameList) throws Exception{
FileOutputStream outputStream = null;
OutputStreamWriter outputStreamWriter = null;
BufferedWriter bufWriter = null;
try
{
//FileOutputStream的第二个参数为true,就是将写入的内容追加到文件末尾
outputStream = new FileOutputStream(tableFile,true);
outputStreamWriter = new OutputStreamWriter(outputStream);
bufWriter = new BufferedWriter(outputStreamWriter);
tableNameList = sortStr(tableNameList);
//在向文件中写入内容之前首先将文件中的内容清空
if(clearFile(tableFile)){
int size = (tableNameList.size()<=maxTableNameNum)?tableNameList.size():maxTableNameNum;
for(int i=0; i<size; i++){
bufWriter.write(tableNameList.get(i));
bufWriter.newLine();
}
}
bufWriter.flush();
return true;
}
catch (FileNotFoundException e)
{
throw e;
}
catch (IOException e)
{
throw e;
}
catch (Exception e)
{
throw e;
}finally{
if(outputStream != null){
outputStream.close();
outputStream = null;
}
if(outputStreamWriter != null){
outputStreamWriter.close();
outputStreamWriter = null;
}
if(bufWriter != null){
bufWriter.close();
bufWriter = null;
}
}
}
//字符串排序算法（降序排列）
public List<String> sortStr(List<String> strList){
String tempStr = null;
for(int i=0; i<strList.size(); i++){
for(int j=0; j<(strList.size()-1) - i; j++){
//降序排列
if((strList.get(j).compareTo(strList.get(j+1)))<0 ){
tempStr = strList.get(j);
strList.set(j, strList.get(j+1));
strList.set(j+1, tempStr);
}
tempStr = null;
}
}
return strList;
}
public boolean clearFile(File file) throws Exception{
FileOutputStream outputStream = null;
OutputStreamWriter outputStreamWriter = null;
BufferedWriter bufWriter = null;
try
{
outputStream = new FileOutputStream(file);
outputStreamWriter = new OutputStreamWriter(outputStream);
bufWriter = new BufferedWriter(outputStreamWriter);
bufWriter.write("");
bufWriter.flush();
return true;
}
catch (FileNotFoundException e)
{
throw e;
}
catch (IOException e)
{
throw e;
}finally{
try
{
if(outputStream != null){
outputStream.close();
outputStream = null;
}
if(outputStreamWriter != null){
outputStreamWriter.close();
outputStreamWriter = null;
}
if(bufWriter != null){
bufWriter.close();
bufWriter = null;
}
}
catch (Exception e)
{
throw e;
}
}
}
//给配置文件中增加表名
public boolean tableNameAdd(String tableName) throws Exception{
try
{
List<String> fileList = readFile();
int fileSize = 0;
fileSize = fileList.size();
if(fileSize >= maxTableNameNum){
if(!fileList.contains(tableName)){
fileList.set((maxTableNameNum-1), tableName);
}
}else{
if(!fileList.contains(tableName)){
fileList.add(fileSize, tableName);
}
}
return writeFile(fileList);
}
catch (Exception e)
{
throw e;
}
}
//删除配置文件中的表名
public boolean tableNameDel(String tableName) throws Exception {
boolean result = false;
try
{
List<String> tableNameList = readFile();
if(tableNameList.contains(tableName)){//删除的表名在配置文件中存在
tableNameList.remove(tableName);
result = writeFile(tableNameList);
}else{//删除的表名不存在
result = false;
}
return result;
}
catch (IOException e)
{
throw e;
}
catch (Exception e)
{
throw e;
}
}
//得到配置文件中的tablename集合列表
public List<String> tableNameList() throws IOException{
return readFile();
}
}