Java generates and exports JSON files

Convert a list collection to a JSON file and export:

Data collection:
New Arraylist<object>();        MapNew hashmap<>();        Agencymap.put ("Agencyname", agencyname);        Agencymap.put ("agencyaddress", agencyaddress);        Agencymap.put ("CompanyName", companyName);        Agencymap.put ("Logoimageid", Logoimageid);        Agencymap.put ("auctionaddress", agencyauctionaddress);        Agencymap.put ("Logoimage", logoimage);        Agencylist.add (AGENCYMAP);

　　　　
Convert the collection data to a JSON string (of course the map collection is also possible):
Jsonarray jsonobject = jsonarray.fromobject (agencylist);         = jsonobject.tostring ();        " /filestorage/download/json "," agency ");

 Public classCreatefileutil {/*** generate. json format Files*/     Public Static Booleancreatejsonfile (String jsonstring, String FilePath, String fileName) {//Mark whether the file was generated successfully        BooleanFlag =true; //stitching file Full pathString FullPath = filePath + file.separator + fileName + ". JSON"; //generate JSON-formatted files        Try {            //guaranteed to create a new fileFile File =NewFile (FullPath); if(!file.getparentfile (). exists ()) {//If the parent directory does not exist, create a parent directoryfile.getparentfile (). Mkdirs (); }            if(File.exists ()) {//if it already exists, delete the old fileFile.delete ();            } file.createnewfile (); if(Jsonstring.indexof ("'")!=-1){                  //Escape the single quotation mark because the string type in the JSON string can be quoted in single quotation marksjsonstring = Jsonstring.replaceall ("'", "\ \" ")); }              if(Jsonstring.indexof ("\" ")!=-1){                  //escape the double quotes because the string types in the JSON string can be quoted in single quotesjsonstring = Jsonstring.replaceall ("\" "," \\\ ""); }                            if(Jsonstring.indexof ("\ r \ n")!=-1){                  //convert carriage return to newline because strings in the JSON string cannot have an explicit return line breakjsonstring = Jsonstring.replaceall ("\ r \ n", "\\u000d\\u000a"); }              if(Jsonstring.indexof ("\ n")!=-1){                  //convert a line break because a string in the JSON string cannot have an explicit line breakjsonstring = Jsonstring.replaceall ("\ n", "\\u000a"); }                          //formatting a JSON stringJsonstring =Jsonformattool.formatjson (jsonstring); //writes a formatted string to a fileWriter Write =NewOutputStreamWriter (NewFileOutputStream (file), "UTF-8");            Write.write (jsonstring);            Write.flush ();        Write.close (); } Catch(Exception e) {flag=false;        E.printstacktrace (); }        //returns whether the token was successful        returnFlag; }       }

 Public classJsonformattool {/*** Units indent strings. */    Private StaticString SPACE = ""; /*** Returns the formatted JSON string. *      * @paramJSON unformatted JSON string. * @returna formatted JSON string. */     Public Staticstring Formatjson (String json) {StringBuffer result=NewStringBuffer (); intLength =json.length (); intNumber = 0; CharKey = 0; //iterates through the input string.          for(inti = 0; i < length; i++) {            //1. Gets the current character. Key =Json.charat (i); //2, if the current character is the front bracket, the preceding curly braces to do the following processing:            if(Key = = ' [') | | (Key = = ' {'))) {                //(1) If there are characters in front, and the character is ":", Print: NewLine and indent character strings.                 if((i-1 > 0) && (json.charat (i-1) = = ': ') {result.append (' \ n ');                Result.append (indent (number)); }                //(2) Print: The current character. result.append (key); //(3) The front bracket, the front curly brace, must be followed by a newline. Print: Line break. Result.append (' \ n '); //(4) Each occurrence of a front bracket, the front curly brace, the number of indents increased once. Print: New line indent. number++;                Result.append (indent (number)); //(5) Proceed to the next cycle.                 Continue; }            //3, if the current character is the rear bracket, after the curly braces do the following processing:            if(key = = '] ') | | (Key = = '} ')) {                //(1) The rear brackets, after curly braces, must be wrapped in front. Print: Line break. Result.append (' \ n '); //(2) Each appearance of the rear bracket, after curly braces, the number of indents decreased once. Print: Indent. number--;                Result.append (indent (number)); //(3) Print: The current character. result.append (key); //(4) If there are characters after the current character, and the characters are not ",", Print: Line wrapping.                 if((((i + 1) < length) && (Json.charat (i + 1)! = ', ') {result.append (' \ n '); }                //(5) continue the next cycle.                 Continue; }            //4, if the current character is a comma. The comma is followed by a newline and indented without changing the indent count.             /*if ((key = = ', ')) {result.append (key);                Result.append (' \ n ');                Result.append (indent (number));            Continue }*/            //5, Print: The current character. result.append (key); }        returnresult.tostring (); }    /*** Returns the indentation string for a specified number of times.     Each time you indent three spaces, space. *      * @paramnumber indent count. * @returnA String that specifies the number of indents. */    Private StaticString Indent (intNumber ) {StringBuffer result=NewStringBuffer ();  for(inti = 0; I < number; i++) {result.append (SPACE); }        returnresult.tostring (); }}

Of course, it involves escaping character handling issues.

Java generates and exports JSON files