将FileWriter的编码设置为UTF-8 [重复]

Question

这个问题已经在这里有了答案 ：

使用FileWriter（Java）以UTF-8格式编写文件吗？ （9个答案）

2年前关闭。

下面是我的代码，它打算获取两个.ckl文件，比较两个文件，添加新项目并创建一个新的合并文件。该程序在Netbeans中运行时可以正确执行，但是，当执行.jar时，该程序似乎未使用UTF-8编码文件。我对编程很陌生，想知道在什么地方或如何执行这种编码？

**我删除了Swing代码和其他行，以便仅显示我的方法，该方法完成所有比较和合并。

public void mergeFiles(File[] files, File mergedFile) {

    ArrayList<String> list = new ArrayList<String>();

    FileWriter fstream = null;
    BufferedWriter out = null;
    try {
        fstream = new FileWriter(mergedFile, false);
        out = new BufferedWriter(fstream);
      } catch (IOException e1) {
        e1.printStackTrace();
    }
    // Going in a different direction. We are using a couple booleans to tell us when we want to copy or not. So at the beginning since we start
    // with our source file we set copy to true, we want to copy everything and insert vuln names into our list as we go. After that first file 
    // we set the boolean to false so that we dont start copying anything from the second file until it is a vuln. We set to true when we see vuln
    // and set it to false if we already have that in our list. 
    // We have a tmpCopy to store away the value of copy when we see a vuln, and reset it to that value when we see an </VULN>
    Boolean copy = true;
    Boolean tmpCopy = true;
    for (File f : files) {
        textArea1.append("merging files into: " + mergedFilePathway + "\n");
        FileInputStream fis;
        try {
            fis = new FileInputStream(f);
//                BufferedReader in = new BufferedReader(new InputStreamReader(new FileInputStream(mergedFile), "UTF-8"));
            BufferedReader in = new BufferedReader(new InputStreamReader(fis));
            String aLine;
            while ((aLine = in.readLine()) != null) {
                // Skip the close checklist and we can write it in at the end
                if (aLine.trim().equals("</iSTIG>")) {
                    continue;
                }
                if (aLine.trim().equals("</STIGS>")) {
                    continue;
                }
                if (aLine.trim().equals("</CHECKLIST>")) {
                    continue;
                }
                if (aLine.trim().equals("<VULN>")) {
                    // Store our current value of copy
                    tmpCopy = copy;
                    copy = true;
                    String aLine2 = in.readLine();
                    String aLine3 = in.readLine();
                    String nameLine = in.readLine();

                    if (list.contains(nameLine.trim())) {
                        textArea1.append("Skipping: " + nameLine + "\n");
                        copy = false;
                        while (!(aLine.trim().equals("</VULN>"))) {
                            aLine = in.readLine();
                        }
                        continue; // this would skip the writing out to file part
                    } else {
                        list.add(nameLine.trim());
                        textArea1.append("::: List is now :::");
                        textArea1.append(list.toString() + "\n");
                    }
                    if (copy) {
                        out.write(aLine);
                        out.newLine();
                        out.write(aLine2);
                        out.newLine();
                        out.write(aLine3);
                        out.newLine();
                        out.write(nameLine);
                        out.newLine();
                    }
                } else if (copy) {
                    out.write(aLine);
                    out.newLine();
                }
                // after we have written to file, if the line was a close vuln, switch copy back to original value
                if (aLine.trim().equals("</VULN>")) {
                    copy = tmpCopy;
                }
            }

            in.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
        copy = false;
    }

    // Now lets add the close checklist tag we omitted before
    try {
        out.write("</iSTIG>");
        out.write("</STIGS>");
        out.write("</CHECKLIST>");
    } catch (IOException e) {
        e.printStackTrace();
    }

    try {
        out.close();
    } catch (IOException e) {
        e.printStackTrace();
    }

}

Answer 1

Java具有广泛的，内容丰富的文档。保留书签。遇到困难时，请先参考它。您会发现它经常有用。

在这种情况下，FileWriter的文档说：

此类的构造函数假定默认字符编码和默认字节缓冲区大小是可接受的。要自己指定这些值，请在FileOutputStream上构造一个OutputStreamWriter。

如果您要确保文件将以UTF-8格式编写，请替换为：

FileWriter fstream = null;
BufferedWriter out = null;
try {
    fstream = new FileWriter(mergedFile, false);

有了这个：

Writer fstream = null;
BufferedWriter out = null;
try {
    fstream = new OutputStreamWriter(new FileOutputStream(mergedFile), StandardCharsets.UTF_8);