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java如何转utf

2026-03-24 00:50:35Java

转换字符串为UTF-8编码

在Java中，字符串默认使用UTF-16编码。若需转换为UTF-8编码的字节数组，可使用String类的getBytes方法并指定编码：

String originalString = "需要转换的字符串";
byte[] utf8Bytes = originalString.getBytes(StandardCharsets.UTF_8);

读取文件并转换为UTF-8

使用InputStreamReader和BufferedReader读取非UTF-8编码文件时，可指定输出编码为UTF-8：

try (BufferedReader reader = new BufferedReader(
    new InputStreamReader(new FileInputStream("input.txt"), "ISO-8859-1"))) {
    String line;
    while ((line = reader.readLine()) != null) {
        byte[] utf8Bytes = line.getBytes(StandardCharsets.UTF_8);
        // 处理UTF-8字节或重新转为字符串
    }
}

写入UTF-8编码文件

通过OutputStreamWriter将内容以UTF-8编码写入文件：

try (Writer writer = new BufferedWriter(
    new OutputStreamWriter(new FileOutputStream("output.txt"), StandardCharsets.UTF_8))) {
    writer.write("UTF-8编码的内容");
}

处理HTTP请求的UTF-8编码

在Servlet中设置请求和响应的UTF-8编码：

// 设置请求编码
request.setCharacterEncoding("UTF-8");
// 设置响应编码
response.setCharacterEncoding("UTF-8");
response.setContentType("text/html; charset=UTF-8");

转换其他编码至UTF-8

若源数据为其他编码（如GBK），需先按原编码解码再转为UTF-8：

java如何转utf

byte[] gbkBytes = "字符串".getBytes("GBK");
String decodedString = new String(gbkBytes, "GBK");
byte[] utf8Bytes = decodedString.getBytes(StandardCharsets.UTF_8);