前言
日志信息对于程序员的作用我就不多说了，好的日志信息对于程序的调试，调优有着不可小觑的作用。随着项目的进展，你可能越发觉得安卓自带的日志类 android.util.Log 不能满足项目的需求，需要深度定制适合自己项目的 Logger 。
如果你有以下的需求：
1. 将 Android 日志信息记录到一个文件里面
2. 深度定制化或者控制日志的显示，例如在发布产品后，考虑到性能，你需要阻止所有的日志信息
那么该文章将尤其适合你。 本文章我将整合使用 android.util.Log 以及经典的 log4j 进行深度定制化日志管理。
项目实践
项目准备：
0. Android开发环境(Eclipse + ADT + AndroidSDK + ...)
1. 下载 log4j JAR包
2. 阅读相关文档，设置好开发环境(导入 log4j JAR包)
项目说明：
该项目主要包括三个类:
1. CLogger.java
2. CLogConfiguration.java
3. CLoggerHelper.java
深度定制化或者控制日志的显示
这一小节中，我们将创建一个 Android-Logger 的 Android Project ，需要实现程序员可以控制 LogCat 中打印日志的类型。
LoggerActivity.java -> 用于测试
CLogger.java -> 用于自定义 Logger ，封装 android.util.Log
CLogConfiguration.java -> 用于定义 Logger 的配置信息
CLogger中我们定义的类型Level级别： VERBOSE < DEBUG < INFO < EARN < ERROR < What a Terrible Failure
首先我们看一下测试类 LoggerActivity.java
1 public class LoggerActivity extends Activity {
2
3 private static final String TAG = "LoggerActivity";
4
5 @Override
6 public void onCreate(Bundle savedInstanceState) {
7 super.onCreate(savedInstanceState);
8 setContentView(R.layout.activity_logger);
9
10 CLogConfiguration logConfiguration = new CLogConfiguration();
11 logConfiguration.setLogcatLogShownLevel(Level.ERROR_INT);
12 CLogger.setLogConfiguration(logConfiguration);
13
14 CLogger.v(TAG, "this is a VERBOSE log");
15 CLogger.d(TAG, "this is a DEBUG log");
16 CLogger.i(TAG, "this is a INFO log");
17 CLogger.w(TAG, "this is a WARN log");
18 CLogger.e(TAG, "this is a ERROR log");
19 CLogger.wtf(TAG, "this is a What a Terrible Failure log");
20 }
21 }
2
3 private static final String TAG = "LoggerActivity";
4
5 @Override
6 public void onCreate(Bundle savedInstanceState) {
7 super.onCreate(savedInstanceState);
8 setContentView(R.layout.activity_logger);
9
10 CLogConfiguration logConfiguration = new CLogConfiguration();
11 logConfiguration.setLogcatLogShownLevel(Level.ERROR_INT);
12 CLogger.setLogConfiguration(logConfiguration);
13
14 CLogger.v(TAG, "this is a VERBOSE log");
15 CLogger.d(TAG, "this is a DEBUG log");
16 CLogger.i(TAG, "this is a INFO log");
17 CLogger.w(TAG, "this is a WARN log");
18 CLogger.e(TAG, "this is a ERROR log");
19 CLogger.wtf(TAG, "this is a What a Terrible Failure log");
20 }
21 }
备注：
1. 第 14 ～ 19 行定义需要测试的 CLogger 类型
2. 第 12 行将 CLogConfiguration 信息设置到 CLogger 中
3. 第 10 ～ 11 行定义 CLogConfiguration 对象， 此处 logConfiguration.setLogcatLogShownLevel(Level.ERROR_INT)， 那么只显示 "this is a ERROR log" 和 "this is a What a Terrible Failure log"。 如果将 "Level.ERROR_INT" 改为 "Level.DEBUG_INT"，那么将会显示 "this is a DEBUG log", "this is a INFO log", "this is a WARN log", "this is a ERROR log", "this is a What a Terrible Failure log"。
然后我们看一下 CLogger.java 类
1 public class CLogger {
2 private static CLogConfiguration logConfiguration = new CLogConfiguration();
3
4 public static void setLogConfiguration(CLogConfiguration logConfiguration) {
5 CLogger.logConfiguration = logConfiguration;
6 }
7
8 public static void configure() {
9 logConfiguration.configure();
10 }
11
12 protected static String generateMessage(String tag, String msg) {
13 tag = tag == null ? "" : tag;
14 msg = msg == null ? "" : msg;
15 return "(" + tag + ") " + msg;
16 }
17
18 /**
19 * Send a VERBOSE log message and log the exception.
20 *
21 * @param tag
22 * Used to identify the source of a log message.
23 * @param msg
24 * The message you would like logged.
25 */
26 public static int v(String tag, String msg) {
27 if (logConfiguration.getLogcatLogShownLevel() < Level.DEBUG_INT) {
28 return Log.v(tag, msg);
29 }
30 return 0;
31 }
32
33 /**
34 * Send a VERBOSE log message and log the exception.
35 *
36 * @param tag
37 * Used to identify the source of a log message.
38 * @param msg
39 * The message you would like logged.
40 * @param tr
41 * An exception to log.
42 */
43 public static int v(String tag, String msg, Throwable tr) {
44 if (logConfiguration.getLogcatLogShownLevel() < Level.DEBUG_INT) {
45 return Log.v(tag, msg, tr);
46 }
47 return 0;
48 }
49
50 /**
51 * Send a DEBUG log message and log the exception.
52 *
53 * @param tag
54 * Used to identify the source of a log message.
55 * @param msg
56 * The message you would like logged.
57 */
58 public static int d(String tag, String msg) {
59 if (logConfiguration.getLogcatLogShownLevel() < Level.INFO_INT) {
60 return Log.d(tag, msg);
61 }
62 return 0;
63 }
64
65 /**
66 * Send a DEBUG log message and log the exception.
67 *
68 * @param tag
69 * Used to identify the source of a log message.
70 * @param msg
71 * The message you would like logged.
72 * @param tr
73 * An exception to log.
74 */
75 public static int d(String tag, String msg, Throwable tr) {
76 if (logConfiguration.getLogcatLogShownLevel() < Level.INFO_INT) {
77 return Log.d(tag, msg, tr);
78 }
79 return 0;
80 }
81
82 /**
83 * Send a INFO log message and log the exception.
84 *
85 * @param tag
86 * Used to identify the source of a log message.
87 * @param msg
88 * The message you would like logged.
89 */
90 public static int i(String tag, String msg) {
91 if (logConfiguration.getLogcatLogShownLevel() < Level.WARN_INT) {
92 return Log.i(tag, msg);
93 }
94 return 0;
95 }
96
97 /**
98 * Send a INFO log message and log the exception.
99 *
100 * @param tag
101 * Used to identify the source of a log message.
102 * @param msg
103 * The message you would like logged.
104 * @param tr
105 * An exception to log.
106 */
107 public static int i(String tag, String msg, Throwable tr) {
108 if (logConfiguration.getLogcatLogShownLevel() < Level.WARN_INT) {
109 return Log.i(tag, msg, tr);
110 }
111 return 0;
112 }
113
114 /**
115 * Send a WARN log message and log the exception.
116 *
117 * @param tag
118 * Used to identify the source of a log message.
119 * @param msg
120 * The message you would like logged.
121 */
122 public static int w(String tag, String msg) {
123 if (logConfiguration.getLogcatLogShownLevel() < Level.ERROR_INT) {
124 return Log.w(tag, msg);
125 }
126 return 0;
127 }
128
129 /**
130 * Send a WARN log message and log the exception.
131 *
132 * @param tag
133 * Used to identify the source of a log message.
134 * @param msg
135 * The message you would like logged.
136 * @param tr
137 * An exception to log.
138 */
139 public static int w(String tag, String msg, Throwable tr) {
140 if (logConfiguration.getLogcatLogShownLevel() < Level.ERROR_INT) {
141 return Log.w(tag, msg, tr);
142 }
143 return 0;
144 }
145
146 /**
147 * Send a ERROR log message and log the exception.
148 *
149 * @param tag
150 * Used to identify the source of a log message.
151 * @param msg
152 * The message you would like logged.
153 */
154 public static int e(String tag, String msg) {
155 return Log.e(tag, msg);
156 }
157
158 /**
159 * Send a ERROR log message and log the exception.
160 *
161 * @param tag
162 * Used to identify the source of a log message.
163 * @param msg
164 * The message you would like logged.
165 * @param tr
166 * An exception to log.
167 */
168 public static int e(String tag, String msg, Throwable tr) {
169 return Log.e(tag, msg, tr);
170 }
171
172 /**
173 * What a Terrible Failure: Report a condition that should never happen.
174 *
175 * @param tag
176 * Used to identify the source of a log message.
177 * @param tr
178 * An exception to log.
179 */
180 public static int wtf(String tag, Throwable tr) {
181 return Log.wtf(tag, tr);
182 }
183
184 /**
185 * What a Terrible Failure: Report a condition that should never happen.
186 *
187 * @param tag
188 * Used to identify the source of a log message.
189 * @param msg
190 * he message you would like logged.
191 */
192 public static int wtf(String tag, String msg) {
193 return Log.wtf(tag, msg);
194 }
195
196 /**
197 * What a Terrible Failure: Report a condition that should never happen.
198 *
199 * @param tag
200 * Used to identify the source of a log message.
201 * @param msg
202 * he message you would like logged.
203 * @param tr
204 * An exception to log. May be null.
205 */
206 public static int wtf(String tag, String msg, Throwable tr) {
207 return Log.wtf(tag, msg, tr);
208 }
209
210 }
2 private static CLogConfiguration logConfiguration = new CLogConfiguration();
3
4 public static void setLogConfiguration(CLogConfiguration logConfiguration) {
5 CLogger.logConfiguration = logConfiguration;
6 }
7
8 public static void configure() {
9 logConfiguration.configure();
10 }
11
12 protected static String generateMessage(String tag, String msg) {
13 tag = tag == null ? "" : tag;
14 msg = msg == null ? "" : msg;
15 return "(" + tag + ") " + msg;
16 }
17
18 /**
19 * Send a VERBOSE log message and log the exception.
20 *
21 * @param tag
22 * Used to identify the source of a log message.
23 * @param msg
24 * The message you would like logged.
25 */
26 public static int v(String tag, String msg) {
27 if (logConfiguration.getLogcatLogShownLevel() < Level.DEBUG_INT) {
28 return Log.v(tag, msg);
29 }
30 return 0;
31 }
32
33 /**
34 * Send a VERBOSE log message and log the exception.
35 *
36 * @param tag
37 * Used to identify the source of a log message.
38 * @param msg
39 * The message you would like logged.
40 * @param tr
41 * An exception to log.
42 */
43 public static int v(String tag, String msg, Throwable tr) {
44 if (logConfiguration.getLogcatLogShownLevel() < Level.DEBUG_INT) {
45 return Log.v(tag, msg, tr);
46 }
47 return 0;
48 }
49
50 /**
51 * Send a DEBUG log message and log the exception.
52 *
53 * @param tag
54 * Used to identify the source of a log message.
55 * @param msg
56 * The message you would like logged.
57 */
58 public static int d(String tag, String msg) {
59 if (logConfiguration.getLogcatLogShownLevel() < Level.INFO_INT) {
60 return Log.d(tag, msg);
61 }
62 return 0;
63 }
64
65 /**
66 * Send a DEBUG log message and log the exception.
67 *
68 * @param tag
69 * Used to identify the source of a log message.
70 * @param msg
71 * The message you would like logged.
72 * @param tr
73 * An exception to log.
74 */
75 public static int d(String tag, String msg, Throwable tr) {
76 if (logConfiguration.getLogcatLogShownLevel() < Level.INFO_INT) {
77 return Log.d(tag, msg, tr);
78 }
79 return 0;
80 }
81
82 /**
83 * Send a INFO log message and log the exception.
84 *
85 * @param tag
86 * Used to identify the source of a log message.
87 * @param msg
88 * The message you would like logged.
89 */
90 public static int i(String tag, String msg) {
91 if (logConfiguration.getLogcatLogShownLevel() < Level.WARN_INT) {
92 return Log.i(tag, msg);
93 }
94 return 0;
95 }
96
97 /**
98 * Send a INFO log message and log the exception.
99 *
100 * @param tag
101 * Used to identify the source of a log message.
102 * @param msg
103 * The message you would like logged.
104 * @param tr
105 * An exception to log.
106 */
107 public static int i(String tag, String msg, Throwable tr) {
108 if (logConfiguration.getLogcatLogShownLevel() < Level.WARN_INT) {
109 return Log.i(tag, msg, tr);
110 }
111 return 0;
112 }
113
114 /**
115 * Send a WARN log message and log the exception.
116 *
117 * @param tag
118 * Used to identify the source of a log message.
119 * @param msg
120 * The message you would like logged.
121 */
122 public static int w(String tag, String msg) {
123 if (logConfiguration.getLogcatLogShownLevel() < Level.ERROR_INT) {
124 return Log.w(tag, msg);
125 }
126 return 0;
127 }
128
129 /**
130 * Send a WARN log message and log the exception.
131 *
132 * @param tag
133 * Used to identify the source of a log message.
134 * @param msg
135 * The message you would like logged.
136 * @param tr
137 * An exception to log.
138 */
139 public static int w(String tag, String msg, Throwable tr) {
140 if (logConfiguration.getLogcatLogShownLevel() < Level.ERROR_INT) {
141 return Log.w(tag, msg, tr);
142 }
143 return 0;
144 }
145
146 /**
147 * Send a ERROR log message and log the exception.
148 *
149 * @param tag
150 * Used to identify the source of a log message.
151 * @param msg
152 * The message you would like logged.
153 */
154 public static int e(String tag, String msg) {
155 return Log.e(tag, msg);
156 }
157
158 /**
159 * Send a ERROR log message and log the exception.
160 *
161 * @param tag
162 * Used to identify the source of a log message.
163 * @param msg
164 * The message you would like logged.
165 * @param tr
166 * An exception to log.
167 */
168 public static int e(String tag, String msg, Throwable tr) {
169 return Log.e(tag, msg, tr);
170 }
171
172 /**
173 * What a Terrible Failure: Report a condition that should never happen.
174 *
175 * @param tag
176 * Used to identify the source of a log message.
177 * @param tr
178 * An exception to log.
179 */
180 public static int wtf(String tag, Throwable tr) {
181 return Log.wtf(tag, tr);
182 }
183
184 /**
185 * What a Terrible Failure: Report a condition that should never happen.
186 *
187 * @param tag
188 * Used to identify the source of a log message.
189 * @param msg
190 * he message you would like logged.
191 */
192 public static int wtf(String tag, String msg) {
193 return Log.wtf(tag, msg);
194 }
195
196 /**
197 * What a Terrible Failure: Report a condition that should never happen.
198 *
199 * @param tag
200 * Used to identify the source of a log message.
201 * @param msg
202 * he message you would like logged.
203 * @param tr
204 * An exception to log. May be null.
205 */
206 public static int wtf(String tag, String msg, Throwable tr) {
207 return Log.wtf(tag, msg, tr);
208 }
209
210 }