StringBuiler&String.Format簡単なテスト

basejunit.java

protected void configure(Class<?> clazz) {
		PropertyConfigurator.configure(getLog4jConfiguration(clazz));
	}

	private Properties getLog4jConfiguration(Class<?> clazz) {
		Properties prop = new Properties();
		String className = clazz.getSimpleName().toLowerCase();
		prop.setProperty(String.format("log4j.logger.%s",clazz.getPackage().getName()+"."+clazz.getSimpleName()), String.format("info,%s", className));
		prop.setProperty(String.format("log4j.appender.%s",className), "org.apache.log4j.FileAppender");
		prop.setProperty(String.format("log4j.appender.%s.layout",className), "org.apache.log4j.PatternLayout");		
		prop.setProperty(String.format("log4j.appender.%s.file",className), String.format("%s.log",clazz.getResource("").toString().replace("file:/", "")+"log/"+className));
		prop.setProperty(String.format("log4j.appender.%s.layout.ConversionPattern",className), "%d %p [%c] - %m%n");
		
		return prop;
	}

StringFormantAndStringBuildTest.java

public class StringFormantAndStringBuildTest extends BaseJunit {
	private Log log = null;
	private long stamp=0;
	int maxTime=100;
	
	public StringFormantAndStringBuildTest(){
		log = LogFactory.getLog(this.getClass());
		super.configure(this.getClass());
	}
	@Before
	public void step(){
	}
	
	@Test
	public void StringFormatTest(){
		stamp=System.currentTimeMillis();
		StringBuilder testString=new StringBuilder();
		Random random=new Random();
		Object[] obj=new Object[maxTime];
		for (int i=0 ;i<maxTime;i++){
			testString.append("%s_");
			obj[i]=random.nextLong();
		}
		log.info(String.format(testString.toString(),obj));
		log.info("StringFromat  stamp:"+(System.currentTimeMillis()-stamp));
		
	}
	@Test
	public void StringBuilder(){
		stamp=System.currentTimeMillis();
		StringBuilder testString=new StringBuilder();
		Random random=new Random();
		for (int i=0 ;i<maxTime;i++){
			testString.append(random.nextLong());
			testString.append("-");
		}
		log.info(testString.toString());
		log.info("StringBuilder  stamp:"+(System.currentTimeMillis()-stamp));
	}
	@Test
	public void StringBuffer(){
		stamp=System.currentTimeMillis();
		StringBuffer testString=new StringBuffer();
		Random random=new Random();
		for (int i=0 ;i<maxTime;i++){
			testString.append(random.nextLong());
			testString.append("-");
		}
		log.info(testString.toString());
		log.info("StringBuffer  stamp:"+(System.currentTimeMillis()-stamp));
	}
	@Test
	public void String(){
		stamp=System.currentTimeMillis();
		String testString="";
		Random random=new Random();
		for (int i=0 ;i<maxTime;i++){
			testString=testString+random.nextLong()+"-";
		}
		log.info(testString);
		log.info("String  stamp:"+(System.currentTimeMillis()-stamp));
		
	}
}

テスト結果:
mehtod
time
junit_time(s)
log)
String.format
100
0.078
0
StringBuilder
100
0
0
StringBuffer
100
0
0
String+
100
0
0
String.format
1000
0.125
31
StringBuilder
1000
0.016
0
StringBuffer
1000
0
0
String+
1000
0.156
156
String.format
5000
0.172
109
StringBuilder
5000
0.032
32
StringBuffer
5000
0.031
31
String+
5000
16.609
16594
String.format
10000
0.235
172
StringBuilder
10000
0.062
47
StringBuffer
10000
0.047
47
String+
10000
~
129469
次はマルチスレッド同時の状況をテストして、ちょうどいくつかの機会を借りてマルチスレッドを勉強して、どうせよく知らない.