StringBuiler&String.Format 简单的测试

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));
		
	}
}

测试结果：

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

接下去要测试一下多线程并发的情况，刚好借些机会学习多线程，反正很陌生