How to append text to an existing file in Java -

i need append text repeatedly existing file in java. how do that?

are doing logging purposes? if there several libraries this. 2 of popular log4j , logback.

java 7+

if need 1 time, files class makes easy:

try {     files.write(paths.get("myfile.txt"), "the text".getbytes(), standardopenoption.append); }catch (ioexception e) {     //exception handling left exercise reader } 

^{careful: above approach throw nosuchfileexception if file not exist. not append newline automatically (which want when appending text file). steve chambers's answer covers how files class.}

however, if writing same file many times, above has open , close file on disk many times, slow operation. in case, buffered writer better:

try(filewriter fw = new filewriter("myfile.txt", true);     bufferedwriter bw = new bufferedwriter(fw);     printwriter out = new printwriter(bw)) {     out.println("the text");     //more code     out.println("more text");     //more code } catch (ioexception e) {     //exception handling left exercise reader } 

notes:

• the second parameter filewriter constructor tell append file, rather writing new file. (if file not exist, created.)
• using bufferedwriter recommended expensive writer (such filewriter).
• using printwriter gives access println syntax you're used system.out.
• but bufferedwriter , printwriter wrappers not strictly necessary.

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older java

try {     printwriter out = new printwriter(new bufferedwriter(new filewriter("myfile.txt", true)));     out.println("the text");     out.close(); } catch (ioexception e) {     //exception handling left exercise reader } 

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exception handling

if need robust exception handling older java, gets verbose:

filewriter fw = null; bufferedwriter bw = null; printwriter out = null; try {     fw = new filewriter("myfile.txt", true);     bw = new bufferedwriter(fw);     out = new printwriter(bw);     out.println("the text");     out.close(); } catch (ioexception e) {     //exception handling left exercise reader } {     try {         if(out != null)             out.close();     } catch (ioexception e) {         //exception handling left exercise reader     }     try {         if(bw != null)             bw.close();     } catch (ioexception e) {         //exception handling left exercise reader     }     try {         if(fw != null)             fw.close();     } catch (ioexception e) {         //exception handling left exercise reader     } }