Android获取当前应用的运行内存
题外话，最近在给H5游戏做一个缓存的框架，有个小需求是在WebView界面上显示一个调试框，实时显示缓存信息，包括显示当前的内存大小。本来想网上应该一堆的博客介绍的。心想这样子就美滋滋了，也没多想。但是MMP，一把辛酸泪。
把代码拷贝下来后，发现内存获取显示不对，一直往上飙，100M，200M，300M，400M。但是，Android Profiler 内存分析消耗是不变的，真是日了狗了。没办法找原因啊，网上看了看了一大堆分析的，就想问句，代码有验证过么就发出来?!!!
最后，还得自己解决。分析了下Android Profiler 的内存结构：
image.png
由这几部分组成，然后大家再跟看看系统源码的android.os.Debug.MemoryInfo的这个类，哈哈哈，刚好也有相关的内存结构分类说明：(大家自己翻译理解，我不多说了)
/**
* Returns the value of a particular memory statistic or {@code null} if no
* such memory statistic exists.
*
* <p>The following table lists the memory statistics that are supported.
* Note that memory statistics may be added or removed in a future API level.</p>
*
* <table>
* <thead>
* <tr>
* <th>Memory statistic name</th>
* <th>Meaning</th>
* <th>Example</th>
* <th>Supported (API Levels)</th>
* </tr>
* </thead>
* <tbody>
* <tr>
* <td>summary.java-heap</td>
* <td>The private Java Heap usage in kB. This corresponds to the Java Heap field
* in the App Summary section output by dumpsys meminfo.</td>
* <td>{@code 1442}</td>
* <td>23</td>
* </tr>
* <tr>
* <td>summary.native-heap</td>
* <td>The private Native Heap usage in kB. This corresponds to the Native Heap
* field in the App Summary section output by dumpsys meminfo.</td>
* <td>{@code 1442}</td>
* <td>23</td>
* </tr>
* <tr>
* <td>summary.code</td>
* <td>The memory usage for static code and resources in kB. This corresponds to
* the Code field in the App Summary section output by dumpsys meminfo.</td>
* <td>{@code 1442}</td>
* <td>23</td>
* </tr>
* <tr>
* <td>summary.stack</td>
* <td>The stack usage in kB. This corresponds to the Stack field in the
* App Summary section output by dumpsys meminfo.</td>
* <td>{@code 1442}</td>
* <td>23</td>
* </tr>
* <tr>
* <td>summary.graphics</td>
* <td>The graphics usage in kB. This corresponds to the Graphics field in the
* App Summary section output by dumpsys meminfo.</td>
* <td>{@code 1442}</td>
* <td>23</td>
* </tr>
* <tr>
* <td>summary.private-other</td>
* <td>Other private memory usage in kB. This corresponds to the Private Other
* field output in the App Summary section by dumpsys meminfo.</td>
* <td>{@code 1442}</td>
* <td>23</td>
* </tr>
* <tr>
* <td>summary.system</td>
* <td>Shared and system memory usage in kB. This corresponds to the System
* field output in the App Summary section by dumpsys meminfo.</td>
* <td>{@code 1442}</td>
* <td>23</td>
* </tr>
* <tr>
* <td>summary.total-pss</td>
* <td>Total PPS memory usage in kB.</td>
* <td>{@code 1442}</td>
* <td>23</td>
* </tr>
* <tr>
* <td>summary.total-swap</td>
* <td>Total swap usage in kB.</td>
* <td>{@code 1442}</td>
* <td>23</td>
* </tr>
* </tbody>
* </table>
*/
public String getMemoryStat(String statName) {
switch(statName) {
case "summary.java-heap":
return Integer.toString(getSummaryJavaHeap());
case "summary.native-heap":
return Integer.toString(getSummaryNativeHeap());
case "summary.code":
return Integer.toString(getSummaryCode());
case "summary.stack":
return Integer.toString(getSummaryStack());
case "summary.graphics":
return Integer.toString(getSummaryGraphics());
case "summary.private-other":
return Integer.toString(getSummaryPrivateOther());
case "summary.system":
return Integer.toString(getSummarySystem());
case "summary.total-pss":
return Integer.toString(getSummaryTotalPss());
case "summary.total-swap":
return Integer.toString(getSummaryTotalSwap());
default:
return null;
}
}
/**
* Returns a map of the names/values of the memory statistics
* that {@link #getMemoryStat(String)} supports.
*
* @return a map of the names/values of the supported memory statistics.
*/
public Map<String, String> getMemoryStats() {
Map<String, String> stats = new HashMap<String, String>();
stats.put("summary.java-heap", Integer.toString(getSummaryJavaHeap()));
stats.put("summary.native-heap", Integer.toString(getSummaryNativeHeap()));
stats.put("summary.code", Integer.toString(getSummaryCode()));
stats.put("summary.stack", Integer.toString(getSummaryStack()));
stats.put("summary.graphics", Integer.toString(getSummaryGraphics()));
stats.put("summary.private-other", Integer.toString(getSummaryPrivateOther()));
stats.put("summary.system", Integer.toString(getSummarySystem()));
stats.put("summary.total-pss", Integer.toString(getSummaryTotalPss()));
stats.put("summary.total-swap", Integer.toString(getSummaryTotalSwap()));
return stats;
}
到这里，我们就可以解决问题了，只需要获取到对应的信息就可以了,下面代码供大家参考下。
@TargetApi(Build.VERSION_CODES.M)
private double getRunningMemory() {
double mem = 0.0D;
try {
// 统计进程的内存信息 totalPss
final Debug.MemoryInfo[] memInfo = activityManager.getProcessMemoryInfo(new int[]{Process.myPid()});
if (memInfo.length > 0) {
/**
* 读取内存信息,跟Android Profiler 分析一致
*/
String java_mem = memInfo[0].getMemoryStat("summary.java-heap");
String native_mem = memInfo[0].getMemoryStat("summary.native-heap");
String graphics_mem = memInfo[0].getMemoryStat("summary.graphics");
String stack_mem = memInfo[0].getMemoryStat("summary.stack");
String code_mem = memInfo[0].getMemoryStat("summary.code");
String others_mem = memInfo[0].getMemoryStat("summary.system");
final int dalvikPss = ConvertUtils.convertToInt(java_mem,0)
+ ConvertUtils.convertToInt(native_mem,0)
+ ConvertUtils.convertToInt(graphics_mem,0)
+ ConvertUtils.convertToInt(stack_mem,0)
+ ConvertUtils.convertToInt(code_mem,0)
+ ConvertUtils.convertToInt(others_mem,0);
if (dalvikPss >= 0) {
// Mem in MB
mem = dalvikPss / 1024.0D;
}
}
} catch (Exception e) {
e.printStackTrace();
}
return mem;
}
/**
* 转化为int
* @param value 传入对象
* @param defaultValue 发生异常时，返回默认值
* @return
*/
public final static int convertToInt(Object value, int defaultValue){
if (value == null || "".equals(value.toString().trim())){
return defaultValue;
}
try {
return Integer.valueOf(value.toString());
}catch (Exception e){
try {
return Integer.valueOf(String.valueOf(value));
}catch (Exception e1) {
try {
return Double.valueOf(value.toString()).intValue();
}catch (Exception e2){
return defaultValue;
}
}
}
}
实践验证上图：
image.png
结语：
当遇到问题的时候，要多看看源码信息，答案就在其中。
