java日常筆記2016 12 27

1：file.separator

file file1 = new file (「c:\tmp\test.txt」);

file myfile = new file(「c:」 + file.separator + 「tmp」 + file.separator, 「test.txt」);

2：過濾器   filefilter

file ff = f.listfiles(new filefilter() {}

is = new fileinputstream(f);

int value = -1;
while((value=is.read())!=-1)

is = new fileinputstream(f);

int value = -1;
byte tong = new byte[512];
while((value=is.read(tong)) !=-1)

第一種：獲取類載入的根路徑   d:\git\daotie\daotie\target\classes

file f = new file(this.getclass().getresource("/").getpath());

第三種：  file:/d:/git/daotie/daotie/target/classes/

url xmlpath = this.getclass().getclassloader().getresource("");

6：

//資源路徑有兩種方式， 

//1:一種以 / 開頭，則這樣的路徑是指定絕對路徑，
//2:如果不以 / 開頭， 則路徑是相對與這個class所在的包的
public class relation_absolute 

/*

* 以  	位元組流	 形式讀取properties檔案
*/public class readpropertiesdemo_stream else
}}		
for (string key : map.keyset()) 
}	private static string gettxtcontentfrompath(string path) 
} catch (unsupportedencodingexception e)  catch (ioexception e) 
}		return strb.tostring();
}

/*

* 以	字元流	的形式讀屬性檔案
*  */
public class readpropertiesdemo_reader 
if((row!=null&&row.trim().length()>0)&&!row.trim().startswith("#"))else}}
for (string key : map.keyset()) 
} catch (unsupportedencodingexception e)  catch (ioexception e) 
}

/*

* 位元組流
*/public class inputstreamdemo 
} catch (filenotfoundexception e)  catch (ioexception e) finally
} catch (ioexception e) 
}}	}

/*

* 輸出流
*/public class outputstreamdemo 
file fileout = new file(dir,123456+".txt");
long currenttimemillis = system.currenttimemillis();
if(filein.exists())
system.out.println(system.currenttimemillis() - currenttimemillis);
} catch (filenotfoundexception e)  catch (ioexception e) finally
} catch (ioexception e) 
try 
} catch (ioexception e) 
}}	}

/*

* 基本的字元流讀複製文字
*/public class copy_print 
fileout.createnewfile();
//先得到位元組流,轉換成字元流,這樣可以設定編碼
reader reader = new inputstreamreader(new fileinputstream(filein),"gbk");//new filereader(filein,"gbk");//這個**是錯的，直接讀取文字,不能指定編碼
bufferedreader br = new bufferedreader(reader);
bufferedwriter out = new bufferedwriter(new filewriter(fileout));
while(true)
out.write(txt+"\r\n");
out.flush();
system.out.println(txt);
}		br.close();
out.close();
}

public static void main(string args) throws exception 

fileout.createnewfile();
bufferedreader br = new bufferedreader(new filereader(filein));
//		bufferedwriter out = new bufferedwriter(new filewriter(fileout));
printwriter out = new printwriter(new bufferedwriter(new filewriter(fileout)));
while(true)
system.out.println(txt);
out.println(txt); 
out.flush();//不能省！
}		br.close();
out.close();
}

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