Java异常处理与资源关闭技巧

try {
    FileReader file = new FileReader("data.txt");
    int ch;
    while ((ch = file.read()) != -1) {
        System.out.print((char) ch);
    }
} catch (IOException e) {
    System.err.println("读取文件时发生IO异常：" + e.getMessage());
}

try (FileReader file = new FileReader("data.txt");
     BufferedReader reader = new BufferedReader(file)) {
    
    String line;
    while ((line = reader.readLine()) != null) {
        System.out.println(line);
    }
} catch (IOException e) {
    System.err.println("IO异常：" + e.getMessage());
}

FileReader file = null;
BufferedReader reader = null;
try {
    file = new FileReader("data.txt");
    reader = new BufferedReader(file);
    String line;
    while ((line = reader.readLine()) != null) {
        System.out.println(line);
    }
} catch (IOException e) {
    System.err.println("读取失败：" + e.getMessage());
} finally {
    if (reader != null) {
        try {
            reader.close();
        } catch (IOException e) {
            // 忽略或记录关闭异常
        }
    }
    if (file != null) {
        try {
            file.close();
        } catch (IOException e) {
            // 同上
        }
    }
}

try (ResourceA a = new ResourceA();
     ResourceB b = new ResourceB()) {
    // 使用资源
} catch (IOException e) {
    for (Throwable suppressed : e.getSuppressed()) {
        System.err.println("被抑制的异常：" + suppressed);
    }
}