java 將字符串、list 寫(xiě)入到文件,并讀取內(nèi)容的案例
我就廢話不多說(shuō)了,大家還是直接看代碼吧~
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 { /** * 字符流寫(xiě)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(); } } /** * 字節(jié)輸出到txt * * @param path * @param data */ @SuppressWarnings("resource") public static void FileString2(String path, String data) { try { FileOutputStream outputStream = new FileOutputStream(path);// 字節(jié)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(); } } /** * 設(shè)置編碼格式寫(xiě)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");// 設(shè)置編碼格式 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(); } } /** * 追加寫(xiě)入到txt * * @param path * @param data */ @SuppressWarnings("resource") public static void FileString4(String path, String data) { try { FileOutputStream outputStream = new FileOutputStream(path, true);// 追加寫(xiě)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(); } } /** * 存儲(chǔ)list到文件 * * @param path * @param list */ @SuppressWarnings("resource") public static <T> void FileWriteList1(String path, List<T> 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(); } } /** * 設(shè)置編碼格式存儲(chǔ)list到txt * * @param path * @param list */ @SuppressWarnings("resource") public static <T> void FileWriteList(String path, List<T> list) { try { 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 寫(xiě)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(); } } /** * 讀取本地文件數(shù)據(jù)設(shè)置指定編碼 * * @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")); 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(); } return buffer.toString(); } /** * 根據(jù)字節(jié)讀取文件 * * @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(); } /** * 獲取本地文件中的list * * @param path */ @SuppressWarnings("resource") public static <T> void FileInputList(String path) { try { FileInputStream inputStream = new FileInputStream(path); ObjectInputStream stream = new ObjectInputStream(inputStream); List<T> list = (List<T>) 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(); } } /** * 高效讀取指定編碼格式的文件 * @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(); } }
補(bǔ)充知識(shí):java讀取txt文件為L(zhǎng)ist
文件在桌面放著名字為hello.txt,先看一下要讀取的內(nèi)容
這是為了方便展示demo隨便寫(xiě)的,格式是一行一個(gè)英文單詞,一共五個(gè)。
讀取代碼,這個(gè)代碼也是網(wǎng)上找的,忘了哪個(gè)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:從txt文件讀取List<String> */ public static List<String> getFileContent(String path) { List<String> strList = new ArrayList<String>(); 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<String> fileContent = ReaderFileLine.getFileContent("C:\\Users\\Lenovo\\Desktop\\hello.txt"); for (String s : fileContent) { System.out.println(s); } } }
輸出:
first
second
Third
Fourth
Fifth
注意:
1.這里File這個(gè)類導(dǎo)入的包是Io的,不是Nio的
2. ReaderFileLine.getFileContent("C:\\Users\\Lenovo\\Desktop\\hello.txt"); 這個(gè)路徑是絕對(duì)路徑
3.路徑是一個(gè) 反斜杠 \ 但是在代碼里面反斜杠是轉(zhuǎn)義的意思,所以需要再加一個(gè)\,如果你是用的IDEA恭喜你,它會(huì)自動(dòng)給你加上
以上這篇java 將字符串、list 寫(xiě)入到文件,并讀取內(nèi)容的案例就是小編分享給大家的全部?jī)?nèi)容了,希望能給大家一個(gè)參考,也希望大家多多支持腳本之家。
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