java - 从字符串写入java文件(通过逐行读取文本文件中的字符串内容)

Question

我想将字符串的内容保存到Java文件中。字符串“sttr”的内容是从文本文件中逐行读取的。当我运行代码时，我得到了正确的输出，但是当我尝试将内容写入 Java 文件时，我只得到一行。代码:

String content = " test ";   
String content1 = "test01";
//read text file line by line

try {
    FileInputStream fstream = new FileInputStream("E:\\test\\myfile.txt");
    DataInputStream in = new DataInputStream(fstream);
    BufferedReader br = new BufferedReader(new InputStreamReader(in));

    String strLine;
    String sttr ;
    while ((strLine = br.readLine()) != null)   {
        sttr = strLine;
        System.out.println(content+sttr+content1);

        File file = new File("E:/test/output.java");
        // if file doesnt exists, then create it
        if (!file.exists()) {
            file.createNewFile();
        }

        FileWriter fw = new FileWriter(file.getAbsoluteFile());
        BufferedWriter bw = new BufferedWriter(fw);

        //bw.write(content);
        bw.write(content+sttr+content1);
        //bw.write(content1);
        //bw.close();
        //System.out.println("Done");      
    }
}  
catch (Exception e) { //Catch exception if any
    System.err.println("Error: " + e.getMessage());
}

Answer 1

不要每次都重新创建 BufferedWriter，而是在循环外执行一次。否则，它将删除文件的内容。

File file = new File("E:/test/output.java");
// if file doesnt exists, then create it
if (!file.exists()) {
    file.createNewFile();
}
FileWriter fw = new FileWriter(file.getAbsoluteFile());
BufferedWriter bw = new BufferedWriter(fw);

String strLine;
String sttr ;
while ((strLine = br.readLine()) != null) {
    // [...]