工作中的一些总结,虽然非常简单,但是,用到的地方非常之多。在此分享一些
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(1)把Strings转换成int和把int转换成String
String a = String.valueOf(2);
//integer to numeric string
int i = Integer.parseInt(a); //numeric string to an int
String a = String.valueOf(2);
//integer to numeric string
int i = Integer.parseInt(a); //numeric string to anint
(2)向Java文件中添加文本
public void addFile() {
//Updated: Thanks Simone for pointing to exception. I have changed the code.
BufferedWriter out = null;
try
{
out = new BufferedWriter(new FileWriter("filename", true));
out.write("aString");
} catch (IOException e) {
// error processing code } finally
{
if (out != null) {
try {
out.close();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
}
}
}
(3)获取Java现在正调用的方法名
String methodName =
Thread.currentThread().getStackTrace()[1].getMethodName();
String methodName = Thread.currentThread().getStackTrace()[1].getMethodName();
(4)在Java中将String型转换成Date型
java.util.Date =
java.text.DateFormat.getDateInstance().parse(date String); java.util.Date = java.text.DateFormat.getDateInstance().parse(date
String);or SimpleDateFormat format = new SimpleDateFormat( "dd.MM.yyyy"
); Date date = format.parse( myString ); SimpleDateFormat format = new SimpleDateFormat( "dd.MM.yyyy" );Date date
= format.parse( myString );
(5)6.将Java中的util.Date转换成sql.Date
java.util.Date utilDate = new
java.util.Date(); java.sql.Date sqlDate = new java.
sql.Date
(utilDate.getTime()); java.util.Date utilDate = new java.util.Date();java.sql.Date sqlDate =
new java.sql.Date(utilDate.getTime());
(6)使用NIO快速复制
Java文件
public static void fileCopy( File in, File out )
throws IOException {
FileChannel inChannel = new FileInputStream( in ).getChannel();
FileChannel outChannel = new FileOutputStream( out ).getChannel();
try
{
// inChannel.transferTo
(0, inChannel.size(), outChannel); // original
-- apparently has trouble copying large files on Windows // magic number for Windows, 64Mb - 32Kb)
int maxCount = (64 * 1024 * 1024) - (32 * 1024);
long size =
inChannel.size();
long
position = 0;
while (
position < size )
{
&;nbsp; position += inChannel.transferTo( position, maxCount, outChannel );
}
}
finally
{
if (
inChannel != null )
{
&;nbsp; inChannel.close();
}
if ( outChannel != null )
{
&;nbsp; outChannel.close();
}
}
}
public static void fileCopy( File in, File out )
throws
IOException{FileChannel inChannel = new FileInputStream( in ).getChannel
();FileChannel outChannel = new
FileOutputStream( out ).getChannel();try{// inChannel.transferTo
(0, inChannel.size(), outChannel); // original
-- apparently has trouble copying large files on Windows
// magic number for Windows, 64Mb - 3
2Kb)
int maxCount = (64 * 1024 * 1024) - (32 * 1024);long
size = inChannel.size();
long position = 0;while ( position < size )
{ position += inChannel.transferTo( position, maxCount, outChannel
);}
}
finally{if (
inChannel != null )
{ inChannel.close();}
if (
outChannel != null )
{ outChannel.close();}
}}
(7)在Java中创建缩略图
private void createThumbnail1(String filename, int thumbWidth,
int thumbHeight, int quality, String outFilename)
throws InterruptedException, FileNotFoundException, IOEx