Read the three columns in the TXT file to the matrix.

Import Java. io. bufferedreader; import Java. io. file; import Java. io. filereader; import Java. io. ioexception; import Java. util. *; import Java. io. bufferedwriter; import Java. io. *; // This program implements the function of reading three columns of numbers in a TXT file into a two-dimensional array. Public class Change {public static void main (string [] ARGs) {change a = New Change (); string filename = "D: \ Java \ workspace \ Java \ SRC \ input1.txt ";. readfilebylines (filename, filename + "-out.txt"); system. out. println ("finished... ");} public static void readfilebylines (string filename, string WF) {double [] [] matrix = new double [4] [4]; bufferedreader reader = NULL; // declare the buffer read object bufferedwriter writer = NULL; // Declare the buffer write object try {reader = new bufferedreader (New filereader (filename); writer = new bufferedwriter (New filewriter (WF); string tempstring = NULL; while (tempstring = reader. readline ())! = NULL) // read a row at a time until the end of reading null is {stringtokenizer ST = new stringtokenizer (tempstring); While (St. hasmoretokens () {int I, j = 0; Double A = 0.0; string Nt = ST. nexttoken (); I = integer. parseint (NT); // parse the abscissa if (St. hasmoretokens () {J = integer. parseint (St. nexttoken (); If (St. hasmoretokens () {A = double. parsedouble (St. nexttoken (); If (I <= 9 & J <= 3) {matrix [I] [J] = A;} else {system. out. println ("error") ;}}} reader. close (); For (INT I = 0; I <= 3; I ++) {for (Int J = 0; j <= 3; j ++) {double D = matrix [I] [J]; writer. write (D. tostring () + "\ t");} writer. write ("\ n");} writer. close ();} catch (ioexception e) {e. printstacktrace ();}}}

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