Zdiv's Software Snippet

2018년 3월 26일 월요일

[Link] Java Tutorial

Site Links

1. Java Reference (java2s.com)

Link: http://www.java2s.com/

2. Java Reference (avajava.com)

Link: http://avajava.com/tutorials/

3. Java Tips (javatips.net)

Link: https://www.javatips.net/

2018년 3월 25일 일요일

[Link] Python Tutorial

1. A byte of python

Link: https://python.swaroopch.com/

2. Dive into Python 3

Link: http://www.diveintopython3.net/

[Link] C++ Tutorial

1. C++ Reference (cplusplus.com)

Link: http://www.cplusplus.com/

2. C++ Annotation

Link: http://www.icce.rug.nl/documents/cplusplus/

3. C++ Reference (cppreference.com)

Link: http://en.cppreference.com/w/

[Link] Go Tutorial

1. GoLang-book

Link: https://www.golang-book.com/books/intro
Link: http://codingnuri.com/golang-book/ (한글판)

2. Go by Example

Link: https://gobyexample.com/

3. Go Tutorial (Tutorials Point)

Link: https://www.tutorialspoint.com/go/index.htm

[Android] How to get network status

1. How to get network status

public static void showNetworkStatus(Context context) {
    final ConnectivityManager connMgr = 
            (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
    boolean wifi = connMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI).isAvailable();
    boolean mobile = connMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).isAvailable();
    boolean bluetooth = false;
    if( android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.HONEYCOMB_MR2 ) {            
        bluetooth = connMgr.getNetworkInfo(ConnectivityManager.TYPE_BLUETOOTH).isAvailable();
    }
    Toast.makeText(context, "wifi: " + wifi + ", mobile: " + mobile + ", bluetooth: " + bluetooth
            , Toast.LENGTH_SHORT).show();
}

[Android] How to get display size

1. Get display size in pixel

@SuppressLint("NewApi")
public static void showScreenSizeInPixel( Activity activity ) {
    Display display = activity.getWindowManager().getDefaultDisplay();
    DisplayMetrics outMetrics = new DisplayMetrics ();
    display.getMetrics(outMetrics);
    Toast.makeText( activity
        , "w: " + outMetrics.widthPixels + ", h: " + outMetrics.heightPixels
        , Toast.LENGTH_SHORT).show();
}

Result:

2. Get display size in dp using DisplayMetrics

@SuppressLint("NewApi")
public static void showScreenInfo( Activity activity ) {
    Display display = activity.getWindowManager().getDefaultDisplay();
    DisplayMetrics outMetrics = new DisplayMetrics ();
    display.getMetrics(outMetrics);
    float density  = activity.getResources().getDisplayMetrics().density;
    float dpHeight = outMetrics.heightPixels / density;
    float dpWidth  = outMetrics.widthPixels / density;
    Toast.makeText( activity, 
        "density: " + density + ", wdp: " + dpWidth + ", hdp: " + dpHeight
        , Toast.LENGTH_SHORT).show();
}

Result:

3. Get display size in dp using Configuration

In this method, the screen height is only 615dp which is not same as in DisplayMetrics (640dp), It seems Configuration returns without notification area.

@SuppressLint("NewApi")
public static void showScreenSizeDp( Activity activity ) {
    Configuration configuration = activity.getResources().getConfiguration();
    Toast.makeText( activity, 
        "wdp: " + configuration.screenWidthDp + ", hdp: " + configuration.screenHeightDp
        , Toast.LENGTH_SHORT).show();   }   
}

Result:

[Android] NotificationBar Control

1. NotificationBar Hide

if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN ) {
    getWindow().setFlags(
        WindowManager.LayoutParams.FLAG_FULLSCREEN,
        WindowManager.LayoutParams.FLAG_FULLSCREEN);
} else {
    View decorView = getWindow().getDecorView();
    int uiOptions = View.SYSTEM_UI_FLAG_FULLSCREEN;
    decorView.setSystemUiVisibility(uiOptions);
}

2. NotificationBar Show

if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN ) {
    getWindow().setFlags(
        0, 
        WindowManager.LayoutParams.FLAG_FULLSCREEN);
} else {
    View decorView = getWindow().getDecorView();
    int uiOptions = decorView.getSystemUiVisibility();
    uiOptions &= ~View.SYSTEM_UI_FLAG_FULLSCREEN;
    decorView.setSystemUiVisibility(uiOptions);
}

MainActivity.java

package com.example.actionbar;

import android.annotation.SuppressLint;
import android.os.Build;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;
import android.view.WindowManager;

@SuppressLint("NewApi")
public class MainActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        getActionBar().setTitle("ActionBar Title");
        getActionBar().setSubtitle("ActionBar Subtitle");
    }

    public void onClicNotificationBarHide(View v) {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN ) {
            getWindow().setFlags(
                WindowManager.LayoutParams.FLAG_FULLSCREEN,
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
        } else {
            View decorView = getWindow().getDecorView();
            int uiOptions = View.SYSTEM_UI_FLAG_FULLSCREEN;
            decorView.setSystemUiVisibility(uiOptions);
        }
    }
    
    public void onClicNotificationBarShow(View v) {
        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.JELLY_BEAN ) {
            getWindow().setFlags(
                0, 
                WindowManager.LayoutParams.FLAG_FULLSCREEN);
        } else {
            View decorView = getWindow().getDecorView();
            int uiOptions = decorView.getSystemUiVisibility();
            uiOptions &= ~View.SYSTEM_UI_FLAG_FULLSCREEN;
            decorView.setSystemUiVisibility(uiOptions);
        }
    }   
}

activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Hide NotificationBar"
        android:onClick="onClicNotificationBarHide" />
    
    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="Show NotificationBar"
        android:onClick="onClicNotificationBarShow" />
    
</LinearLayout>

ScreenShot:

1. [Hide NotificationBar] Pressed

2. [Show NotificationBar] Pressed

[Android] ActionBar Control

1. Set ActionBar Title

getActionBar().setTitle("ActionBar Title");

2. Set ActionBar SubTitle

1) show subtitle

getActionBar().setSubtitle("ActionBar Subtitle");

2) remove subtitle

getActionBar().setSubtitle(null);

3. Set ActionBar Icon

getActionBar().setIcon(R.drawable.icon);

4. Hide ActionBar

getActionBar().hide();

5. Show ActionBar

getActionBar().show();

MainActivity.java

package com.example.actionbar;

import android.annotation.SuppressLint;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.View;

@SuppressLint("NewApi")
public class MainActivity extends ActionBarActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        getActionBar().setTitle("ActionBar Title");
        getActionBar().setSubtitle("ActionBar Subtitle");
    }

    public void onClickActionBarHide(View v) {
     getActionBar().hide();
    }
    
    public void onClickActionBarShow(View v) {
     getActionBar().show();
    }   
}

acctivity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <Button
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
        android:text="Hide ActionBar"
        android:onClick="onClickActionBarHide" />
    
    <Button
     android:layout_width="match_parent"
     android:layout_height="wrap_content"
        android:text="Show ActionBar"
        android:onClick="onClickActionBarShow" />
    
</LinearLayout>

ScreenShot:

1. [Hide ActionBar] Pressed

2. [Show ActionBar] Pressed

2018년 3월 24일 토요일

[Java] Download Http File with URL openStream()

1. Download Http File with URL openStream()

package bloggerpostsnippetjava;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Scanner;

public class NetworkHttpUrl {
    
    NetworkHttpUrl() {
    }
    
    String readFromStream( InputStream is ) {
        Scanner scanner;
        scanner = new Scanner( is, "UTF-8" );
        String s = scanner.useDelimiter("\\A").next();
        scanner.close();
        return s; 
    }
    
    String getUrl(String urlStr) throws MalformedURLException, IOException {
        URL url = new URL(urlStr);
        return readFromStream(url.openStream());
    }
    public static void main( String[] args ) {
        try {
            NetworkHttpUrl url = new NetworkHttpUrl();
            String body = url.getUrl("https://www.google.com");
            System.out.println(body);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

2. Http GET with URLConnection()

public class HttpClient {
 
    static void testGet(String urlStr, String param) throws Exception {
        URL url;
        if( param != null ) {
            param = "name=" + URLEncoder.encode(param);
            url = new URL(urlStr + "?" + param);
        } else {
            url = new URL(urlStr);
        }
        URLConnection conn = url.openConnection();
        conn.setUseCaches(false);
        InputStream is = conn.getInputStream();
        Scanner scan = new Scanner(is);
        while(scan.hasNext()) {
            System.out.println(scan.nextLine());
        }
        scan.close();
    }
    
    public static void main(String[] args) {
        try {
            testGet("http://google.com", null);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

3. Http POST with URLConnection()

static void testPost() throws Exception {
        String param = "name=" + URLEncoder.encode("value");
        URL url = new URL("http://www.google.co.kr");
        URLConnection conn = url.openConnection();
        conn.setDoOutput(true);
        conn.setUseCaches(false);
        conn.setRequestProperty("ContentType", "application/x-www-form-urlencoded");
        
        DataOutputStream out = new DataOutputStream(conn.getOutputStream());
        out.writeBytes(param);
        out.flush();
        out.close();
        
        InputStream is = conn.getInputStream();
        Scanner scan = new Scanner(is);
        while(scan.hasNext()) {
            System.out.println(scan.nextLine());
        }
        scan.close();
    }

[Java] PDF Document Creation

Download apache pdfbox-app-2.0.9.jar

1. PDF Document Creation

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;

import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.PDPageContentStream;
import org.apache.pdfbox.pdmodel.PDPageTree;
import org.apache.pdfbox.pdmodel.common.PDRectangle;
import org.apache.pdfbox.pdmodel.font.PDFont;
import org.apache.pdfbox.pdmodel.font.PDType0Font;
import org.apache.pdfbox.pdmodel.font.PDType1Font;
import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject;

public class PdfCreate {

    PDDocument document;
    PDPage page;
    PDPageContentStream stream;
    PDFont font;
    PDFont boldFont;
    PDRectangle pageSize;
    String filename;
    
    int fontSize;
    int topMargin;
    int bottomMargin;
    int leftMargin;
    int rightMargin;
    int currX;
    int currY;
    
    public PdfCreate(String fileName) throws IOException {
        this.document = new PDDocument();
        this.filename = fileName;

        this.topMargin = 72;
        this.bottomMargin = 72;
        this.leftMargin = 36;
        this.rightMargin = 36;

        this.font = PDType1Font.HELVETICA; 
        this.boldFont = PDType1Font.HELVETICA_BOLD; 
        this.fontSize = 14;

        newPage();

    }
    
    public void loadFont(String fontFile, String boldFile) {

        try {
            this.font = PDType0Font.load(document, new File(fontFile));
        } catch (IOException e) {
            this.font = PDType1Font.HELVETICA; 
        }
        try {
            this.boldFont = PDType0Font.load(document, new File(boldFile));
        } catch (IOException e) {
            this.boldFont = PDType1Font.HELVETICA_BOLD; 
        }
    }
        
    public void save() {
        try {
            if( this.stream != null ) {
                this.stream.close();
            }
            this.document.save(this.filename);
            this.document.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }   
    
    private int convY(int y) {
        return getPageHeight() - y - 1;
    }

    public boolean newPage() throws IOException {
        if( this.stream != null ) {
            this.stream.close();
        }
        this.page = new PDPage(PDRectangle.A4);
        this.document.addPage( this.page );
        this.stream = new PDPageContentStream( this.document, this.page );
        this.currX = this.leftMargin;
        this.currY = this.topMargin;    
        return true;
    }
    
    public void pageInfo() {
        PDPageTree pages = this.document.getDocumentCatalog().getPages();
        //pages.get(0);
        //this.document.getPage(0);
        //this.document.getPages();
        printf( "Pages: " + pages.getCount() );
    }
    
    public int getPageWidth() {
        return (int)this.page.getMediaBox().getWidth();
    }

    public int getPageContentWidth() {
        return (int)(getPageWidth() - getLeftMargin() - getRightMargin());
    }
        
    public int getPageHeight() {
        return (int)this.page.getMediaBox().getHeight();
    }

    public int getLeftMargin() {
        return this.leftMargin;
    }

    public int getRightMargin() {
        return this.rightMargin;
    }
    
    public int getTopMargin() {
        return this.topMargin;
    }
    
    public int getBottomMargin() {
        return this.bottomMargin;
    }

    private int getTextWidth( String text ) {
        try {
            return (int)((this.font.getStringWidth(text)/1000)*this.fontSize);
        } catch (IOException e) {
            e.printStackTrace();
            return 0;
        }
    }

    public boolean printText(String text, int color, PDFont textFont) {
        try {   
            List<String> lines = new ArrayList<String>();
            int width = getPageWidth() - getLeftMargin() - getRightMargin();
            int lastSpace = -1;
            while( text.length() > 0 ) {
                int spaceIndex = text.indexOf(' ', lastSpace + 1);
                if (spaceIndex < 0) {
                    spaceIndex = text.length();
                }
                String subString = text.substring(0, spaceIndex);
                float size = this.fontSize * textFont.getStringWidth(subString) / 1000;
                if( size > width ) {
                    if( lastSpace < 0 ) {
                        lastSpace = spaceIndex;
                    }
                    subString = text.substring(0, lastSpace);
                    lines.add(subString);
                    text = text.substring(lastSpace).trim();
                    lastSpace = -1;
                } else if( spaceIndex == text.length() ) {
                    lines.add(text);
                    text = "";
                } else {
                    lastSpace = spaceIndex;
                }
            }

            for (String line: lines) {
                this.stream.beginText();
                this.stream.setFont(textFont, this.fontSize);
                this.stream.setNonStrokingColor((color/0x10000)%0x100, (color/0x100)%0x100, color%0x100);
                this.currY += this.fontSize * 1.5;
                printf("" + getLeftMargin() + "," + this.currY );
                printf(line);
                this.stream.newLineAtOffset( getLeftMargin(), convY(this.currY) );
                this.stream.showText(line);
                this.stream.endText(); 
            }
            return true;
        } catch (IOException e) {
            e.printStackTrace();
            return false;
        }
    }
    
    public boolean printText(String text) {     
        return printText(text, 0, this.font);
    }
    
    public boolean printTextBold(String text) {     
        return printText(text, 0, this.boldFont);
    }

    public boolean printText(String text, int color) {      
        return printText(text, color, this.font);
    }

    public boolean printTextBold(String text, int color) {      
        return printText(text, color, this.boldFont);
    }

    public void drawLine( int x1, int y1, int x2, int y2 ) {
        int width = 1;
        int color = 0;
        try {
            this.stream.setLineWidth(width);
            this.stream.setStrokingColor( (color/0x10000)%0x100, (color/0x100)%0x100, color%0x100);
            this.stream.moveTo( x1, convY((int)y1) );
            this.stream.lineTo( x2, convY((int)y2) );
            this.stream.stroke();
        } catch (IOException e) {
            e.printStackTrace();
        }  
    }
    
    public void printLine() {
        printf("printLine(): " + this.currY);
        drawLine( getLeftMargin(), this.currY, getPageWidth()-getRightMargin(), this.currY);
    }
    
    public int drawImage( float x, float y, String fileName ) {
        try {
            PDImageXObject image = PDImageXObject.createFromFile(fileName, this.document);
            y += image.getHeight();
            this.stream.drawImage(image, x, convY((int)y));
            return image.getHeight();
        } catch (IOException e) {
            e.printStackTrace();
            return 0;
        }       
    }
    
    public void printImage( String fileName ) {
        currY += drawImage( (float)getLeftMargin(), (float)currY, fileName );
    }
    
    void printf(String s) {
        System.out.println(s);
    }
    
    public static void main(String[] args) throws IOException {
        System.out.println("Begin !");
        String s = "I am trying to create a PDF file with a lot of text contents in the document. I am using PDFBox";
        PdfCreate pdf = new PdfCreate("D:/document.pdf");
        pdf.loadFont("malgun.ttf",  "malgunbd.ttf");
        pdf.printLine();
        pdf.printText(s);
        pdf.printImage("D:/image.png");
        pdf.printTextBold(s);
        pdf.printText(s, 0xff0000);
        pdf.printTextBold(s, 0xff0000);
        pdf.printText(" ");
        pdf.printLine();
        pdf.save();
        System.out.println("End !");
    }
}

Output:

2. PDF Document Creation (Old Version)

package javapdfcreate;

import java.io.IOException;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.pdmodel.PDPage;
import org.apache.pdfbox.pdmodel.PDPageContentStream;
import org.apache.pdfbox.pdmodel.common.PDRectangle;
import org.apache.pdfbox.pdmodel.font.PDType1Font;
import org.apache.pdfbox.pdmodel.graphics.image.PDImageXObject;

public class JavaPdfCreate {
    
    PDDocument doc;
    PDPage page;
    PDPageContentStream pageStream;
    
    public JavaPdfCreate() {
        doc = new PDDocument();
    }
    
    public void addPage() throws IOException {
        page = new PDPage(PDRectangle.A4);
        doc.addPage(page);
        if( pageStream != null ) {
            pageStream.close();
        }
        pageStream = new PDPageContentStream( doc, page );
    }
    
    float getPageWidth() {
        return page.getArtBox().getWidth();
    }
    
    float getPageHeight() {
        return page.getArtBox().getHeight();
    }
         
    public void save(String filename) throws IOException {
        if( pageStream != null ) {
            pageStream.close();
        }
        doc.save(filename);
        doc.close();
    }
    
    public void putString( float x, float y, String text, int color ) throws IOException {
        pageStream.beginText();
        pageStream.setFont( PDType1Font.HELVETICA_BOLD, 12 );
        pageStream.moveTextPositionByAmount( x, getPageHeight()-(y+12) );
        pageStream.setNonStrokingColor((color/0x10000)%0xff, (color/0x100)%0xff, color%0xff);
        pageStream.drawString( text ); //new String( text.getBytes("utf-8"), "ksc5601"));
        pageStream.endText();
    }    
    
    public void putLine( float x1, float y1, float x2, float y2, int width, int color ) throws IOException {
        pageStream.setLineWidth(width);
        pageStream.setStrokingColor( (color/0x10000)%0x100, (color/0x100)%0x100, color%0x100);
        pageStream.drawLine( x1, getPageHeight()-y1, x2, getPageHeight()-y2 ); 
    }

    public void putImage( float x, float y, String image, float w, float h ) throws IOException {
        PDImageXObject img = PDImageXObject.createFromFile( image, doc );
        float img_w = w > 0 ? w : img.getWidth();
        float img_h = h > 0 ? h : img.getHeight();
        if( img_w > (getPageWidth()-x) ) {
            float ratio = (getPageWidth()-x) / img_w;
            img_w = (getPageWidth()-x);
            img_h *= ratio;
        }
        pageStream.drawXObject( img, x, getPageHeight()-(y+img_h+1), img_w, img_h );
    }

    public static void main(String[] args) {
        JavaPdfCreate pdf = new JavaPdfCreate();
        try {
            pdf.addPage();
            pdf.putLine( 48.0f, 48.0f, pdf.getPageWidth()-48.0f, 48.0f, 2, 0x000000 );
            pdf.putString( 48.0f, 54.0f, "Hello PdfBox World !", 0x000000 );
            pdf.putImage( 48.0f, 70.0f, "D:/barstack.png", 0, 0);
            pdf.save("D:/a.pdf");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }  
}

Result: (D:/a.pdf)