import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;

public class DataStorage_sp_Activity extends AppCompatActivity {

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

    public void onClick(View view){
        EditText editText =(EditText) findViewById(R.id.editText);
        String text = editText.getText().toString();
        /*       SharedPreferences存储
        * 1.调用SharedPreferences对象的edit()方法，获取SharedPreferences.Editor对象
        * 2.向SharedPreferences.Editor对象中添加数据，put方法（包括基本数据类型与String）
        * 3.调用apply()或commit()方法将添加数据提交到“test”中
        * */
        SharedPreferences.Editor editor = getSharedPreferences("test",MODE_PRIVATE).edit();
        editor.putString("name",text);
     //   editor.apply();
        editor.commit();

        /*    SharedPreferences读取
        * 1.定义SharedPreferences对象
        * 2.从SharedPreferences对象中读取数据，get方法
        * */
        SharedPreferences sp = getSharedPreferences("test",MODE_PRIVATE);
        String name = sp.getString("name","");
        TextView textView =(TextView) findViewById(R.id.textView);
        textView.setText(name);
    }
}

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;  
public class ButtonActivity extends AppCompatActivity implements OnClickListener {

    TextView text;
    @Override

    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_button);
        text = (TextView)findViewById(R.id.btn_out);
        Button btn = (Button)findViewById(R.id.btn);
        btn.setOnClickListener(this);
    }

    public void onClick(View view){
        text.setText("OnClickListener接口");
    }
}

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

public class ButtonActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_button);
        Button btn = (Button)findViewById(R.id.btn);
        final TextView text = (TextView)findViewById(R.id.btn_out);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                text.setText("匿名内部类");
            }
        });
    }
}

import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.TextView;

public class ButtonActivity extends AppCompatActivity {

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

    void MyClick(View btn){
        ((TextView)findViewById(R.id.btn_out)).setText("自定义监听方法");
    }
}

try{
	URL url = new URL("http://www.baidu.com");
}catch(MalformedURLException e){
	System.out.println(e);
}

try{
	URL url = new URL(protocol,host,file);
}catch(MalformedURLException e){
	System.out.println(e);
}

import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.Scanner;
    
public class ReadUrl {

	private static Scanner in;

	public static void main(String[] args) {
		in = new Scanner(System.in);
		Thread readurl;
		URL url;
	    Look look = new Look();
	    System.out.println("请输入URL，例如：http://www.baidu.com:");
	    String string = in.nextLine();
//	    System.out.println("请输入URL协议：");
//	    String protocol = in.next();
//	    System.out.println("请输入URL地址：");
//	    String host = in.next();
	    try{
	    	
	    	url = new URL(string);
	 //   	url = new URL(protocol,host,"");
	    	look.setURL(url);
	    	readurl = new Thread(look);
	    	readurl.start();
	    }catch(Exception e){
	    	System.out.println(e);
	    }
	}

}

class Look implements Runnable{

	URL url;
	public void setURL(URL url) {
		this.url=url;
	}
	@Override
	public void run() {
		// TODO Auto-generated method stub
		try{
			InputStream inputStream = url.openStream();
			byte [] bs = new byte[1024];
			int n = -1;
			while((n=inputStream.read(bs))!=-1){
				String string = new String(bs, 0, n);
				System.out.println(string);
			}
		}catch(IOException e){}
	}
	
}

String strign[] = str.split(regex);

Math.pow(n,m);	//表示n的m次方

Math.sqrt(n);	//表示n的平方根

import java.util.Scanner;

public class test1{

    public static void main(String[] arg){
    
        Scanner in = new Scanner(System.in);
        
        System.out.print("请输入：");
        
        String string  = in.nextLine();
        String string2[] = string.split("\\s");		//单个空格为分隔符
   //   String string2[] = string.split(" ");      //单个空格为分隔符
     //   String string2[] = string.split("[\\s]+");	//单个或多个空格为分隔符
        
        for(int i =0;i<string2.length;i++){
        	System.out.println("整数："+Integer.parseInt(string2[i]));
        	System.out.println("平方："+Math.pow(Integer.parseInt(string2[i]), 2));
        	System.out.println("平方根："+Math.sqrt(Integer.parseInt(string2[i])));
        	
        }
    }
}

请输入：5 7 9 8
整数：5
平方：25.0
平方根：2.23606797749979
整数：7
平方：49.0
平方根：2.6457513110645907
整数：9
平方：81.0
平方根：3.0
整数：8
平方：64.0
平方根：2.8284271247461903

import java.util.Arrays;

public class MergingSort {

	/**
	 * 2-路归并排序：将长度为n的待排序记录看作是一个含有n个长度为1的有序子表，把这些子表以次两两归并，
	 * 			 得到[n/2]个有序的子表；然后再把这[n/2]个有序子表进行两两归并，如此重复，
	 * 			 直到最后得到一个长度为n的有序子表为止。
	 * 空间复杂度为O(n)
	 * 时间复杂度为O(nlogn)
	 * 算法稳定性：2-路归并排序是一种稳定的排序算法
	 * */
	
	/* 两个有序列表的归并算法 */
	public static void Merge(int merge[],int temp[],int m,int n,int k) {
		int i,j;
		int len = n-m+1;		
		for(i=k+1,j=m; m<=k && i<=n; j++){	//将merg中的记录由小到大并入temp
			if(merge[m]<merge[i]){
				temp[j]=merge[m++];
			}
			else {
				temp[j] = merge[i++];
			}
		}
		for(; m<=k; j++){	////将剩余的merge[n...m]复制到temp
			temp[j] = merge[m++];
		}
		for(; i<=n; j++){  //将剩余的merge[i...n]复制到temp
			temp[j] = merge[i++];
		}
		
		for(i=0; i<len; i++){		//将temp复制到merge
			merge[n] = temp[n];
			n--;
		}
	}
	
	/* 2-路归并排序算法 */
	public static void MergeSort(int merge[],int temp[],int m, int n) {
		if(m<n){
			int k = (m+n)/2;
			MergeSort(merge, temp, m, k);		//左边
			MergeSort(merge, temp, k+1, n);		//右边
			Merge(merge, temp, m, n ,k);		//归并两个有序列表
		}
		
	}
	
	public static void MergeSort(int merge[]) {
		MergeSort(merge,new int[merge.length],0,merge.length-1);
	}
	
	public static void main(String[] args) {
		// TODO Auto-generated method stub
		int merge[] = {52,39,67,95,70,8,25,52,56,16};
		MergeSort(merge);
		System.out.println("归并后序列："+Arrays.toString(merge));
	}
}

归并后序列：[8, 16, 25, 39, 52, 52, 56, 67, 70, 95]