public class IoDemo {
public static void main(String[] args) throws IOException { BufferedReader bufr = new BufferedReader(new FileReader("d:\\java\\zz.txt")); BufferedWriter bufw = new BufferedWriter(new FileWriter("d:\\java\\AA.txt")); String str = null; int count = 0; while ((str = bufr.readLine()) != null) { int count2 = getcount(str, "java", 0); // 7 count += count2; // 7 } bufw.write("总个数=" + count); bufw.flush(); bufr.close(); bufw.close(); } public static int getcount(String str, String str2, int count) { int len = str.indexOf("java"); count++; return len == -1 ? count - 1 : getcount(str.substring(len + str2.length()), str2, count); }}
第二种方法：
import java.io.*; import java.util.TreeMap; //简写 public class IoDemo2 { public static void main(String[] args) throws IOException { BufferedReader bufr = new BufferedReader(new FileReader("d:\\java\\zz.txt")); TreeMap<Character, Integer> tp = new TreeMap<>(); int len = 0; while ((len = bufr.read()) != -1) { char ch = (char) len; // if(!tp.containsKey(ch)){ // tp.put(ch,1); // } // else { // tp.put(ch, tp.get(ch)+1); // } tp.put(ch, tp.containsKey(ch) ? tp.get(ch) + 1 : 1); } bufr.read(); BufferedWriter bufw = new BufferedWriter(new FileWriter("d:\\java\\zz22.txt")); for (Character key : tp.keySet()) { if (key == '\r') { bufw.write("\\r" + "=" + tp.get(key)); bufw.newLine(); bufw.flush(); } else if (key == '\n') { bufw.write("\\n" + "=" + tp.get(key)); bufw.newLine(); } else { bufw.write(key + "=" + tp.get(key)); bufw.newLine(); bufw.flush(); } } bufw.close(); } }
