Retrofit打印网络请求日志

用过Retrofit的朋友肯定知道使用Retrofit进行网络网络请求非常的方便简洁，但是要打印网络请求的日志还是要自己另想办法。昨天在网上找了一圈，发现要打印日志，大部分的帖子都是引入OkHttp3的日志库：

compile 'com.squareup.okhttp3:logging-interceptor:3.8.1'

这个库使用起来很简单，在你创建OkHttpClient的时候增加拦截器即可

new OkHttpClient.Builder().connectTimeout(15, TimeUnit.SECONDS).readTimeout(15, TimeUnit.SECONDS).writeTimeout(15, TimeUnit.SECONDS).addInterceptor(new HttpLoggingInterceptor())// 在此处添加拦截器即可，默认日志级别为BASIC.build();

日志级别

日志的级别设置，日志级别包括：NONE(无日志)，BASIC(基础日志)，HEADERS(包含请求头)，BODY(包含请求体)。默认的日志级别是BASIC，最大级别是BODY，会打印整个网络请求的所有信息，让我们来看一下效果：

// Request请求
--> POST http://app.buddha.net.cn/SzgServer/api/getRequestOrder http/1.1     // 请求行
Content-Type: application/x-www-form-urlencoded        // 请求头
Content-Length: 9       // 请求头长度
test=test       // 请求体
--> END POST (9-byte body)
// Response响应
<-- 200 OK http://app.buddha.net.cn/SzgServer/api/getRequestOrder (79ms)
Server: nginx/1.9.3
Date: Sat, 15 Jul 2017 04:00:29 GMT
Content-Type: application/json;charset=UTF-8
Content-Length: 38
Connection: keep-alive
Cache-Control: no-cache, must-revalidate
{"msg":"参数错误","status":"2005"}       // 响应结果
<-- END HTTP (38-byte body)

困惑

以上就是日志级别为BODY所打印出的信息，可以看到非常的全面，包含了Http请求的所有信息，但是！但是！作者并不满足于这种，我想让打印的日志更加直观，就比如说我想把json数据格式化输出，就像这样：

{"msg": "参数错误","status": "2005"
}

由于HttpLoggingInterceptor使用的是安卓自带的Logger来打印日志，所以是不具备把json数据格式化的功能的。这难免会让我们在开发中感到困惑，因为大部分网络请求数据都为json格式，我们希望打印出来的json数据是排版过的可以吗？当然可以，作者决定自己做点小修改，其实也很简单，我们只需要把Logger替换成我们自己的日志框架不就好了吗？现在作者修改后的日志打印如下，作者使用的是KLog，读者可以自行替换：

[ (HttpLoggingInterceptor.java:139)#intercept ] --> POST http://app.buddha.net.cn/SzgServer/api/getRequestOrder http/1.1
[ (HttpLoggingInterceptor.java:146)#intercept ] Content-Type: application/json; charset=UTF-8
[ (HttpLoggingInterceptor.java:149)#intercept ] Content-Length: 25
[ (HttpLoggingInterceptor.java:176)#intercept ]
╔═══════════════════════════════════════════════════════════════════════════════════════
║ [ (HttpLoggingInterceptor.java:178)#intercept ]
║ {
║     "age": 1,
║     "name": "liuwei"
║ }
╚═══════════════════════════════════════════════════════════════════════════════════════
[ (HttpLoggingInterceptor.java:179)#intercept ] --> END POST (25-byte body)
[ (HttpLoggingInterceptor.java:201)#intercept ] <-- 200 OK http://app.buddha.net.cn/SzgServer/api/getRequestOrder (35ms)
[ (HttpLoggingInterceptor.java:208)#intercept ] Server: nginx/1.9.3
[ (HttpLoggingInterceptor.java:208)#intercept ] Date: Sat, 15 Jul 2017 04:17:43 GMT
[ (HttpLoggingInterceptor.java:208)#intercept ] Content-Type: application/json;charset=UTF-8
[ (HttpLoggingInterceptor.java:208)#intercept ] Content-Length: 38
[ (HttpLoggingInterceptor.java:208)#intercept ] Connection: keep-alive
[ (HttpLoggingInterceptor.java:208)#intercept ] Cache-Control: no-cache, must-revalidate
[ (HttpLoggingInterceptor.java:233)#intercept ]
╔═══════════════════════════════════════════════════════════════════════════════════════
║ [ (HttpLoggingInterceptor.java:234)#intercept ]
║ {
║     "msg": "参数错误",
║     "status": "2005"
║ }
╚═══════════════════════════════════════════════════════════════════════════════════════
[ (HttpLoggingInterceptor.java:237)#intercept ] <-- END HTTP (38-byte body)

别的都没变，更换了一下日志框架就让日志输出的这么爽，json结果和requestBody都排版出来了，一眼明了，同样还可以设置日志的级别和自定义修改，美滋滋

自定义的HttpLoggingInterceptor

最后附上修改后的HttpLoggingInterceptor，读者可以自定义日志输出，自己决定打印哪些不打印哪些，很方便：

import com.socks.library.KLog;import java.io.EOFException;
import java.io.IOException;
import java.nio.charset.Charset;
import java.util.concurrent.TimeUnit;
import okhttp3.Connection;
import okhttp3.Headers;
import okhttp3.Interceptor;
import okhttp3.MediaType;
import okhttp3.OkHttpClient;
import okhttp3.Protocol;
import okhttp3.Request;
import okhttp3.RequestBody;
import okhttp3.Response;
import okhttp3.ResponseBody;
import okhttp3.internal.http.HttpHeaders;
import okhttp3.internal.platform.Platform;
import okio.Buffer;
import okio.BufferedSource;import static okhttp3.internal.platform.Platform.INFO;/*** 什么都没做，只是把Logger替换成KLog，读者可自行替换日志框架*/
public final class HttpLoggingInterceptor implements Interceptor {private static final Charset UTF8 = Charset.forName("UTF-8");public enum Level {/** No logs. */NONE,/*** Logs request and response lines.** <p>Example:* <pre>{@code* --> POST /greeting http/1.1 (3-byte body)** <-- 200 OK (22ms, 6-byte body)* }</pre>*/BASIC,/*** Logs request and response lines and their respective headers.** <p>Example:* <pre>{@code* --> POST /greeting http/1.1* Host: example.com* Content-Type: plain/text* Content-Length: 3* --> END POST** <-- 200 OK (22ms)* Content-Type: plain/text* Content-Length: 6* <-- END HTTP* }</pre>*/HEADERS,/*** Logs request and response lines and their respective headers and bodies (if present).** <p>Example:* <pre>{@code* --> POST /greeting http/1.1* Host: example.com* Content-Type: plain/text* Content-Length: 3** Hi?* --> END POST** <-- 200 OK (22ms)* Content-Type: plain/text* Content-Length: 6** Hello!* <-- END HTTP* }</pre>*/BODY}public interface Logger {void log(String message);/** A {@link Logger} defaults output appropriate for the current platform. */Logger DEFAULT = new Logger() {@Override public void log(String message) {Platform.get().log(INFO, message, null);}};}public HttpLoggingInterceptor() {}private volatile Level level = Level.NONE;/** Change the level at which this interceptor logs. */public HttpLoggingInterceptor setLevel(Level level) {if (level == null) throw new NullPointerException("level == null. Use Level.NONE instead.");this.level = level;return this;}public Level getLevel() {return level;}@Override public Response intercept(Chain chain) throws IOException {Level level = this.level;Request request = chain.request();if (level == Level.NONE) {return chain.proceed(request);}boolean logBody = level == Level.BODY;boolean logHeaders = logBody || level == Level.HEADERS;RequestBody requestBody = request.body();boolean hasRequestBody = requestBody != null;Connection connection = chain.connection();Protocol protocol = connection != null ? connection.protocol() : Protocol.HTTP_1_1;String requestStartMessage = "--> " + request.method() + ' ' + request.url() + ' ' + protocol;if (!logHeaders && hasRequestBody) {requestStartMessage += " (" + requestBody.contentLength() + "-byte body)";}KLog.d(requestStartMessage);if (logHeaders) {if (hasRequestBody) {// Request body headers are only present when installed as a network interceptor. Force// them to be included (when available) so there values are known.if (requestBody.contentType() != null) {KLog.d("Content-Type: " + requestBody.contentType());}if (requestBody.contentLength() != -1) {KLog.d("Content-Length: " + requestBody.contentLength());}}Headers headers = request.headers();for (int i = 0, count = headers.size(); i < count; i++) {String name = headers.name(i);// Skip headers from the request body as they are explicitly logged above.if (!"Content-Type".equalsIgnoreCase(name) && !"Content-Length".equalsIgnoreCase(name)) {KLog.d(name + ": " + headers.value(i));}}if (!logBody || !hasRequestBody) {KLog.d("--> END " + request.method());} else if (bodyEncoded(request.headers())) {KLog.d("--> END " + request.method() + " (encoded body omitted)");} else {Buffer buffer = new Buffer();requestBody.writeTo(buffer);Charset charset = UTF8;MediaType contentType = requestBody.contentType();if (contentType != null) {charset = contentType.charset(UTF8);}KLog.d("");if (isPlaintext(buffer)) {KLog.json(buffer.readString(charset));KLog.d("--> END " + request.method()+ " (" + requestBody.contentLength() + "-byte body)");} else {KLog.d("--> END " + request.method() + " (binary "+ requestBody.contentLength() + "-byte body omitted)");}}}long startNs = System.nanoTime();Response response;try {response = chain.proceed(request);} catch (Exception e) {KLog.d("<-- HTTP FAILED: " + e);throw e;}long tookMs = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - startNs);ResponseBody responseBody = response.body();long contentLength = responseBody.contentLength();String bodySize = contentLength != -1 ? contentLength + "-byte" : "unknown-length";KLog.d("<-- " + response.code() + ' ' + response.message() + ' '+ response.request().url() + " (" + tookMs + "ms" + (!logHeaders ? ", "+ bodySize + " body" : "") + ')');if (logHeaders) {Headers headers = response.headers();for (int i = 0, count = headers.size(); i < count; i++) {KLog.d(headers.name(i) + ": " + headers.value(i));}if (!logBody || !HttpHeaders.hasBody(response)) {KLog.d("<-- END HTTP");} else if (bodyEncoded(response.headers())) {KLog.d("<-- END HTTP (encoded body omitted)");} else {BufferedSource source = responseBody.source();source.request(Long.MAX_VALUE); // Buffer the entire body.Buffer buffer = source.buffer();Charset charset = UTF8;MediaType contentType = responseBody.contentType();if (contentType != null) {charset = contentType.charset(UTF8);}if (!isPlaintext(buffer)) {KLog.d("");KLog.d("<-- END HTTP (binary " + buffer.size() + "-byte body omitted)");return response;}if (contentLength != 0) {KLog.d("");KLog.json(buffer.clone().readString(charset));}KLog.d("<-- END HTTP (" + buffer.size() + "-byte body)");}}return response;}/*** Returns true if the body in question probably contains human readable text. Uses a small sample* of code points to detect unicode control characters commonly used in binary file signatures.*/static boolean isPlaintext(Buffer buffer) {try {Buffer prefix = new Buffer();long byteCount = buffer.size() < 64 ? buffer.size() : 64;buffer.copyTo(prefix, 0, byteCount);for (int i = 0; i < 16; i++) {if (prefix.exhausted()) {break;}int codePoint = prefix.readUtf8CodePoint();if (Character.isISOControl(codePoint) && !Character.isWhitespace(codePoint)) {return false;}}return true;} catch (EOFException e) {return false; // Truncated UTF-8 sequence.}}private boolean bodyEncoded(Headers headers) {String contentEncoding = headers.get("Content-Encoding");return contentEncoding != null && !contentEncoding.equalsIgnoreCase("identity");}
}