让异常处理代码更健壮

// 写一句注释跳过异常
try {
    throw new IOException("Made up");
} catch (IOException e) {
    // 跳过
}
// 记到日志里，继续处理
try {
    throw new IOException("Made up");
} catch (IOException e) {
    log.error("blah blah blah", e);
}
// 标记 TODO，不做任何处理
try {
    throw new IOException("Made up");
} catch (IOException e) {
    // TODO - 处理异常 (;
}

// 转换
try {
    throw new IOException("Made up");
} catch (IOException e) {
    throw new RuntimeException(e);
}
// 重试5次后放弃
boolean end = false;
int count = 0;
while (end == false) {
    try {
        // 发送信息
        if (true) {
            throw new MessagingException("Made up");
        }
        end = true;
    } catch (MessagingException e) {
        if (count >= 5) {
            // 尝试5次放弃。
            throw new RuntimeException("was not able to send message even after five tries", e);
        }
        ++count;
        try {
            Thread.sleep(30000);
        } catch (InterruptedException e1) {
            Thread.currentThread().interrupt();
            throw new RuntimeException(e1);
        }
    }
}
// 恢复：如果传输失败记录到文件
try {
    // 发送信息
    throw new MessagingException("Made up");
} catch (MessagingException e) {
    try {
        // 写文件
        throw new IOException("Made up");
    } catch (IOException e1) {
        // 如果写文件失败，不再进行恢复
        throw new RuntimeException(e1);
    }
}