Java测试当前应用所占用的内存示例
package test;
import java.util.HashMap;
import java.util.Map;
public
class TestMemory {
public
static
void
main(String[] args) { System.
gc();
long total = Runtime.
getRuntime().
totalMemory();
// byte
long m1 = Runtime.
getRuntime().
freeMemory(); System.
out.
println(
"before:"
+ (total - m1)); Map<Double,Double> map =
new HashMap<Double,Double>();
for(
int i=
0; i <
1e6; i++){ map.
put(
new Double(Math.
random()*
1e9),
new Double(Math.
random()*
1e10)); }
long total1 = Runtime.
getRuntime().
totalMemory();
long m2 = Runtime.
getRuntime().
freeMemory(); System.
out.
println
(
"after:" + (total1 - m2));
// System.out.println(map.toString()); System.
exit(
0); } }