java关于Txt文件读取和修改.docx

package utils; import java.io.BufferedReader; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.FileOutputStream; import java.io.FileReader; import java.io.IOException; import java.io.InputStreamReader; import java.io.PrintWriter; public class MyFile { @SuppressWarnings(static-access) private static String path = txt/; private static String filenameTemp; /** * 创建文件 * * @throws IOException */ public static boolean creatTxtFile(String name) throws IOException { boolean flag = false; filenameTemp = path + name + .txt; File filename = new File(filenameTemp); if (!filename.exists()) { filename.createNewFile(); flag = true; } return flag; } /** * 写文件 * * @param newStr * 新内容 * @throws IOException */ public static boolean writeTxtFile(String newStr) throws IOException { // 先读取原有文件内容，然后进行写入操作 boolean flag = false; String filein = newStr + \r\n; String temp = ; FileInputStream fis = null; InputStreamReader isr = null; BufferedReader br = null; FileOutputStream fos = null; PrintWriter pw = null; try { // 文件路径 File file = new File(filenameTemp); // 将文件读入输入流 fis = new FileInputStream(file); isr = new InputStreamReader(fis); br = new BufferedReader(isr); StringBuffer buf = new StringBuffer(); // 保存该文件原有的内容 for (int j = 1; (temp = br.readLine()) != null; j++) { buf = buf.append(temp); // System.getProperty(line.separator) // 行与行之间的分隔符 相当于“\n” buf = buf.append(System.getProperty(line.separator)); } buf.append(filein); fos = new FileOutputStream(file); pw = new PrintWriter(