java 将字符串、list 写入到文件,并读取内容的案例

java 将字符串、list 写入到文件,并读取内容的案例

我就废话不多说了，大家还是直接看代码吧~

import java.io.BufferedReader;

import java.io.BufferedWriter;

import java.io.FileInputStream;

import java.io.FileNotFoundException;

import java.io.FileOutputStream;

import java.io.FileWriter;

import java.io.IOException;

import java.io.InputStreamReader;

import java.io.ObjectInputStream;

import java.io.ObjectOutputStream;

import java.io.OutputStreamWriter;

import java.io.StreamCorruptedException;

import java.io.UnsupportedEncodingException;

import java.util.List;

import android.graphics.Bitmap;

public class FileUtils {

/**

* 字符流写入字符串到txt

*/

@SuppressWarnings("resource")

public static void FileString(String path, String data) {

try {

FileWriter writer = new FileWriter(path);// 字符流

writer.write(data);

writer.close();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

/**

* 字节输出到txt

*

* @param path

* @param data

*/

@SuppressWarnings("resource")

public static void FileString2(String path, String data) {

try {

FileOutputStream outputStream = new FileOutputStream(path);// 字节流

outputStream.write(data.getBytes());

outputStream.close();

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

/**

* 设置编码格式写出到txt

*

* @param path

* @param data

*/

public static void FileString3(String path, String data) {

try {

OutputStreamWriter writer = new OutputStreamWriter(new FileOutputStream(path), "UTF-8");// 设置编码格式

writer.write(data);

writer.close();

} catch (UnsupportedEncodingException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

/**

* 追加写入到txt

*

* @param path

* @param data

*/

@SuppressWarnings("resource")

public static void FileString4(String path, String data) {

try {

FileOutputStream outputStream = new FileOutputStream(path, true);// 追加写入

outputStream.write(("\r\n" + data).getBytes());

outputStream.close();

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

/**

* 存储list到文件

*

* @param path

* @param list

*/

@SuppressWarnings("resource")

public static void FileWriteList1(String path, List list) {

try {

FileOutputStream outputStream = new FileOutputStream(path);

ObjectOutputStream stream = new ObjectOutputStream(outputStream);

stream.writeObject(list);

stream.close();

outputStream.close();

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

/**

* 设置编码格式存储list到txt

*

* @param path

* @param list

*/

@SuppressWarnings("resource")

public static void FileWriteList(String path, List list) {

try {

http:// BufferedWriter bufferedWriter = new BufferedWriter(

new OutputStreamWriter(new FileOutputStream(path), "UTF-8"));

for (T s : list) {

bufferedWriter.write(s.toString());

bufferedWriter.newLine();

bufferedWriter.flush();

}

bufferedWriter.close();

} catch (UnsupportedEncodingException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

/**

* bitmap 写入到本地

*

* @param path

* @param bitmap

*/

@SuppressWarnings("resource")

public static void FileBitmap(String path, Bitmap bitmap) {

try {

FileOutputStream outputStream = new FileOutputStream(path);

bitmap.compress(Bitmap.CompressFormat.PNG, 100, outputStream);

outputStream.flush();

outputStream.close();

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

/**

* 读取本地文件数据设置指定编码

*

* @param path

*/

@SuppressWarnings("resource")

public static String FileInputString(String path) {

StringBuffer buffer = new StringBuffer();

try {

BufferedReader reader = new BufferedReader(new InputStreamReader(new FileInputStream(path), "UTF-8"))http://;

String data = null;

while ((data = reader.readLine()) != null) {

buffer.append(data + "\r\n");

}

reader.close();

} catch (UnsupportedEncodingException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

http:// return buffer.toString();

}

/**

* 根据字节读取文件

*

* @param path

* @return

*/

@SuppressWarnings("resource")

public static String FileInputString2(String path) {

StringBuffer buffer = new StringBuffer();

try {

FileInputStream inputStream = new FileInputStream(path);

byte[] bytes = new byte[1024];

int bytead = 0;

while ((bytead = inputStream.read(bytes)) != -1) {

buffer.append(new String(bytes, 0, bytead));

}

inputStream.close();

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

return buffer.toString();

}

/**

* 获取本地文件中的list

*

* @param path

*/

@SuppressWarnings("resource")

public static void FileInputList(String path) {

try {

FileInputStream inputStream = new FileInputStream(path);

ObjectInputStream stream = new ObjectInputStream(inputStream);

List list = (List) stream.readObject();

inputStream.close();

stream.close();

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (StreamCorruptedException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (ClassNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

/**

* 高效读取指定编码格式的文件

* @param path

* @return

*/

@SuppressWarnings("resource")

public static String FileInput3(String path) {

StringBuffer buffer = new StringBuffer();

try {

BufferedReader bufferedReader = new BufferedReader(

new InputStreamReader(new FileInputStream(path), "UTF-8"));

String data = null;

while ((data = bufferedReader.readLine()) != null) {

buffer.append(data+"\r\n");

}

bufferedReader.close();

} catch (UnsupportedEncodingException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

return buffer.toString();

}

}

补充知识：java读取txt文件为List

文件在桌面放着名字为hello.txt,先看一下要读取的内容

这是为了方便展示demo随便写的，格式是一行一个英文单词，一共五个。

读取代码，这个代码也是网上找的，忘了哪个博客了。

import java.io.*;

import java.util.ArrayList;

import java.util.List;

/**

* @author :

* @date : 2018/8/30

* @description:

*/

public class ReaderFileLine {

/**

* @author:

* @date:2018/8/30

* @description:从txt文件读取List

*/

public static List getFileContent(String path) {

List strList = new ArrayList();

File file = new File(path);

InputStreamReader read = null;

BufferedReader reader = null;

try {

read = new InputStreamReader(new FileInputStream(file),"utf-8");

reader = new BufferedReader(read);

String line;

while ((line = reader.readLine()) != null) {

strList.add(line);

}

} catch (UnsupportedEncodingException e) {

e.printStackTrace();

} catch (FileNotFoundException e) {

e.printStackTrace();

} catch (IOException e) {

e.printStackTrace();

} finally {

if (read != null) {

try {

read.close();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

if (reader != null) {

try {

reader.close();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

return strList;

}

public static void main(String[] args) {

List fileContent =

ReaderFileLine.getFileContent("C:\\Users\\Lenovo\\Desktop\\hello.txt");

for (String s : fileContent) {

System.out.println(s);

}

}

}

输出：

first

second

Third

Fourth

Fifth

注意：

1.这里File这个类导入的包是Io的，不是Nio的

2. ReaderFileLine.getFileContent("C:\\Users\\Lenovo\\Desktop\\hello.txt"); 这个路径是绝对路径

3.路径是一个 反斜杠 \ 但是在代码里面反斜杠是转义的意思，所以需要再加一个\,如果你是用的IDEA恭喜你，它会自动给你加上

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