package com.wsn.chapter18javaio;

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;


public class MainActivity extends AppCompatActivity {
    public final static String TAG = "MainActivity";

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);


        //practice 18.1 见DirList.java
        //practice 18.2 见SortedDirList.java
        //practice 18.3 见DirList.java
        //practice 18.4 Directory.java
        //practice 18.5 ProcessFiles.java
        //practice 18.6 见ProcessFiles.java
        //practice 18.7 Pracise7.java
        //practice 18.8 Pracise8.java
        //practice 18.9 Practise9.java
        //practice 18.10 Practise10.java
        //practice 18.11 GreenhouseController.java
        //practice 18.12 Practise12.java
        //practice 18.13 BasicFileOutput.java
        //practice 18.14 BasicFileOutput14.java
        //practice 18.15 StoringAndRecoveringData.java
        //practice 18.16 UsingRandomAccessFile.java
        //practice 18.17 Practise17.java
        //practice 18.18 TextFile18.java
        //practice 18.19 Practise19.java
        //practice 18.20 Practise20.java


    }
}

@@ -1234,16 +1234,51 @@
 20.java%0A
+        //practice 18.21 Echo.java%0A
 %0A%0A    %7D%0A

完成练习18.21