20個(gè)非常有用的Java程序片段

3.得到當(dāng)前方法的名字1.字符串有整型的相互轉(zhuǎn)換Stringa=String.valueOf(2);//integertonumericstringinti=Integer.parseInt(a);//numericstringtoanint2.向文件末尾添加內(nèi)容BufferedWriterout=null;try{out=newBufferedWriter(newFileWriter(”filename”,true));out.write(”aString”);}catch(IOExceptione){y}}StringmethodName=Thread.currentThread().getStackTrace()[1].getMethodName();4.轉(zhuǎn)字符串到日期java.util.Date=java.text.DateFormat.getDateInstance().parse(dateString);或者是：SimpleDateFormatformat=newSimpleDateFormat("dd.MM.yyyy");Datedate=format.parse(myString);5.使用JDBC鏈接OraclepublicclassOracleJdbcTest{StringdriverClass="oracle.jdbc.driver.OracleDriver";amfsthrows{ser}{ualTEt{}}{}6.把Javautil.Date轉(zhuǎn)成sql.DatepublicstaticvoidfileCopy(Filein,Fileout){{inChanneltransferToinChannelsizeoutChannel;//original--while(position<size){}}{{}{}}{HTo}}bjectandwityalseJSONtry{}}meProxyURLeProxyPortmeUserNamesomePassword//toavoiddirectinstantiation.eSingleton}aticSimpleSingletongetInstance}}}publicvoidcaptureScreen(StringfileName)throwsException{mensionscreenSizeToolkitgetDefaultToolkitgetScreenSize}tory}}Thisexampledoesnotreturnanyfilesthatstartwith`.'.r}eresturnsdirectorieser}erpreimportjava.io.;publicclassZipIt{}}ini}}}e}}tublicclassXMLParsertringfileNametry{s{{;+++}}}}}}}17.把Array轉(zhuǎn)換成Mapimportjava.util.*;Systemoutprintln("CapitalofJapanis"+}vaxmailimporternet.;throwsMessagingException{sionsionSessiongetDefaultInstancepropsnullromnewInternetAddressfromssaddressTonewhpientslengthi{}mheadersintheEmailrMyHeaderNamemyHeaderValuemessagetextplaineraderpublicclassMaint}}}?Reallocatesanarraywithanewsize,andcopiesthecontents?oftheoldarraytothenewarray.?@paramoldArraytheoldarray,tobereallocated.?@paramnewSizethenewarraysize.?@returnAnewarraywiththesamecontents.?*/?intoldSize=java.lang.reflect.Array.getLength(oldArray);?ClasselementType=oldArray.getClass().getComponentType();ObjectnewArrayjavalangreflectArraynewInstance???intpreserveLength=Math.