| 利用webView加载超长图 |
android |
|
public static int showLargeImageView(WebView large, String url,
String bitmapPath) {
large.setVisibility(View.VISIBLE);
if (large.getTag() != null) {
return 0;
}
large.getSettings().setJavaScriptEnabled(true);
large.getSettings().setUseWideViewPort(true);
large.getSettings().setLoadWithOverviewMode(true);
large.getSettings().setBuiltInZoomControls(true);
large.getSettings().setDisplayZoomControls(false);
large.setVerticalScrollBarEnabled(false);
large.setHorizontalScrollBarEnabled(false);
File file = new File(bitmapPath);
if (file == null) {
return -1;
}
String str1 = "file://"
+ file.getAbsolutePath().replace("/mnt/sdcard/", "/sdcard/");
String str2 = "<html>\n<head>\n <style>\n html,body{background:transparent;margin:0;padding:0;} *{-webkit-tap-highlight-color:rgba(0, 0, 0, 0);}\n </style>\n <script type=\"text/javascript\">\n var imgUrl = \""
+ str1
+ "\";"
+ " var objImage = new Image();\n"
+ " var realWidth = 0;\n"
+ " var realHeight = 0;\n"
+ "\n"
+ " function onLoad() {\n"
+ " objImage.onload = function() {\n"
+ " realWidth = objImage.width;\n"
+ " realHeight = objImage.height;\n"
+ "\n"
+ " document.gagImg.src = imgUrl;\n"
+ " onResize();\n"
+ " }\n"
+ " objImage.src = imgUrl;\n"
+ " }\n"
+ "\n"
+ " function onResize() {\n"
+ " var scale = 1;\n"
+ " var newWidth = document.gagImg.width;\n"
+ " if (realWidth > newWidth) {\n"
+ " scale = realWidth / newWidth;\n"
+ " } else {\n"
+ " scale = newWidth / realWidth;\n"
+ " }\n"
+ "\n"
+ " hiddenHeight = Math.ceil(30 * scale);\n"
+ " document.getElementById('hiddenBar').style.height = hiddenHeight + \"px\";\n"
+ " document.getElementById('hiddenBar').style.marginTop = -hiddenHeight + \"px\";\n"
+ " }\n"
+ " </script>\n"
+ "</head>\n"
+ "<body onload=\"onLoad()\" onresize=\"onResize()\" onclick=\"Android.toggleOverlayDisplay();\">\n"
+ " <table style=\"width: 100%;height:100%;\">\n"
+ " <tr style=\"width: 100%;\">\n"
+ " <td valign=\"middle\" align=\"center\" style=\"width: 100%;\">\n"
+ " <div style=\"display:block\">\n"
+ " <img name=\"gagImg\" src=\"\" width=\"100%\" style=\"\" />\n"
+ " </div>\n"
+ " <div id=\"hiddenBar\" style=\"position:absolute; width: 100%; background: transparent;\"></div>\n"
+ " </td>\n"
+ " </tr>\n"
+ " </table>\n" + "</body>\n" + "</html>";
large.loadDataWithBaseURL("file:///android_asset/", str2, "text/html",
"utf-8", null);
large.setVisibility(View.VISIBLE);
large.setTag(new Object());
return 1;
}
|
| 保存图片至相册 |
android |
|
/**
* 将bitmap保存至相册
* photoName：照片名称
* bitmap：要保存的图像
* */
public static void savePhotoToAlbum(Context context, String photoName,
Bitmap bitmap) {
// 创建contentValuse对象，保存相片属性
ContentValues values = new ContentValues(7);
// 相片标题
values.put(Images.Media.TITLE,
context.getResources().getString(R.string.app_name));
// 相片名称
values.put(Images.Media.DISPLAY_NAME, photoName);
// 相片类型
values.put(Images.Media.MIME_TYPE, "image/jpeg");
// 相片方向
values.put(Images.Media.ORIENTATION, 0);
// 相片拍摄时间
String saveTime = DateFormat.format(DateTimeUtil.PATTERN_CURRENT_TIME,
System.currentTimeMillis()).toString();
values.put(Images.Media.DATE_TAKEN, saveTime);
// 相片路径
final String CAMERA_IMAGE_BUCKET_NAME = Environment
.getExternalStorageDirectory().getPath() + "dcim/camera";
File parentFile = new File(CAMERA_IMAGE_BUCKET_NAME);
String name = parentFile.getName().toLowerCase();
values.put(Images.ImageColumns.BUCKET_DISPLAY_NAME, name);
// 相片ID
final String CAMERA_IMAGE_BUCKET_ID = String
.valueOf(CAMERA_IMAGE_BUCKET_NAME.hashCode());
values.put(Images.ImageColumns.BUCKET_ID, CAMERA_IMAGE_BUCKET_ID);
// 将contentValuse转化为Uri
Uri dataUri = context.getContentResolver().insert(
MediaStore.Images.Media.EXTERNAL_CONTENT_URI, values);
// 根据Uri将图片写入相册
try {
OutputStream outStream = context.getContentResolver()
.openOutputStream(dataUri);
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, outStream);
outStream.close();
bitmap.recycle();
SuperToast.show("保存图片成功,请到相册查看!", context);
return;
} catch (Exception e) {
SuperToast.show("保存图片失败,请查看网络!", context);
}
}
|
| 图片等比例缩小 |
android |
|
public static Bitmap getResizedBitmap(Bitmap bitmap, int height, int width) {
int h = bitmap.getHeight();
int w = bitmap.getWidth();
if (w >= h && w >= width) {
float ratio = (float) (height) / h;
h = height;
w = (int) (ratio * w);
} else if (h > w && h > height) {
float ratio = (float) (width) / w;
w = width;
h = (int) (ratio * h);
}
Bitmap resizedBitmap = Bitmap.createScaledBitmap(bitmap, w, h, true);
return resizedBitmap;
}
|
| 根据bitmap或者file创建图片并等比例压缩 |
android |
|
public static Bitmap createImg(byte[] aImgBytes) {
BitmapFactory.Options bitopt = new BitmapFactory.Options();
bitopt.inJustDecodeBounds = false;
Bitmap bit = null;
try {
bit = BitmapFactory.decodeByteArray(aImgBytes, 0, aImgBytes.length,bitopt);
} catch (OutOfMemoryError e) {
bit = null;
}
int _resizeTimes = 0;
int w = bitopt.outWidth / 2;
int h = bitopt.outHeight / 2;
while (null == bit) {
bit = shrinkMethod(aImgBytes, w, h);
_resizeTimes++;
if (_resizeTimes > 5) {
return bit;
}
w = w / 2;
h = h / 2;
}
return bit;
}
private static Bitmap shrinkMethod(byte[] aImgByte, int width, int height) {
Bitmap bit = null;
BitmapFactory.Options bitopt = new BitmapFactory.Options();
bitopt.inJustDecodeBounds = true;
BitmapFactory.decodeByteArray(aImgByte, 0, aImgByte.length, bitopt);
if (width == 0) {
width = 1;
}
if (height == 0) {
height = 1;
}
int h = (int) Math.ceil(bitopt.outHeight / width);
int w = (int) Math.ceil(bitopt.outWidth / height);
if (h > 1 || w > 1) {
if (h > w) {
bitopt.inSampleSize = h;
} else {
bitopt.inSampleSize = w;
}
}
bitopt.inJustDecodeBounds = false;
try {
bit = BitmapFactory.decodeByteArray(aImgByte, 0, aImgByte.length,bitopt);
} catch (OutOfMemoryError e) {
bit = null;
}
return bit;
}
public static Bitmap createImg(File aFile) {
BitmapFactory.Options bitopt = new BitmapFactory.Options();
bitopt.inJustDecodeBounds = false;
Bitmap bit = null;
try {
bit = BitmapFactory.decodeFile(aFile.getAbsolutePath(), bitopt);
} catch (OutOfMemoryError e) {
bit = null;
}
if (null == bit) {
bitopt.inJustDecodeBounds = true;
BitmapFactory.decodeFile(aFile.getAbsolutePath(), bitopt);
}
int _resizeTimes = 0;
int w = bitopt.outWidth / 2;
int h = bitopt.outHeight / 2;
while (null == bit) {
bit = shrinkMethod(aFile, w, h);
_resizeTimes++;
if (_resizeTimes > 5) {
return bit;
}
w = w / 2;
h = h / 2;
}
return bit;
}
public static Bitmap shrinkMethod(File aFile, int width, int height) {
Bitmap bit = null;
BitmapFactory.Options bitopt = new BitmapFactory.Options();
bitopt.inJustDecodeBounds = true;
BitmapFactory.decodeFile(aFile.getAbsolutePath(), bitopt);
if (width == 0) {
width = 1;
}
if (height == 0) {
height = 1;
}
int h = (int) Math.ceil(bitopt.outHeight / width);
int w = (int) Math.ceil(bitopt.outWidth / height);
if (h > 1 || w > 1) {
if (h > w) {
bitopt.inSampleSize = h;
} else {
bitopt.inSampleSize = w;
}
}
bitopt.inJustDecodeBounds = false;
try {
bit = BitmapFactory.decodeFile(aFile.getAbsolutePath(), bitopt);
} catch (OutOfMemoryError e) {
bit = null;
}
return bit;
}
|
| 小算法-（水仙花字符串） |
算法 |
求大家帮忙啊，小弟算法不行 |
public class Solution {
public static int symmetryPoint(String s) {
if (s.length() % 2 != 0) {
String leftValue = "";
String rightValue = "";
String str = String.valueOf(s.charAt(s.length() / 2));
String[] split = s.split(str);
for (int i = split[0].length() - 1; i >= 0; i--)
leftValue += split[0].charAt(i);
rightValue = split[1];
if (leftValue.equals(rightValue))
return s.indexOf(str);
else
return -1;
} else
return -1;
}
public static void main(String[] args) {
System.out.println(symmetryPoint("aa21eaxae12aa"));
}
}
|
| servlet实现登陆验证的过滤器 |
servlet编程 |
|
package hellow;
/*
* 本程序用来实现登陆验证的过滤器:
* 首先取得session，然后验证属性是否存在，如果存在，则继续传递请求，否则，转向登陆页面
* */
import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;
public class LoginFilter implements Filter{
public void init(FilterConfig config) throws ServletException {
}
@Override
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain fc) throws IOException, ServletException {
HttpServletRequest req=(HttpServletRequest)request;
HttpSession ses=req.getSession();
if(ses.getAttribute("userid")!=null){
fc.doFilter(request, response);
}else{
request.getRequestDispatcher("login.jsp").forward(request, response);
}
}
public void destroy() {
}
}
|
| 正则表达式基础 |
java语言 |
|
package 正则表达式;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/*
* 此程序的目的是熟悉正则表达式的使用过程：
* 首先：使用字符串建立Pattern(模式)
* 然后：创建Matcher(匹配器)对象，该对象可以与任何对象匹配，多个匹配器可以共享一个模式
* 一般的调用顺序为：
* Pattern p = Pattern.compile("a*b");
Matcher m = p.matcher("aaaaab");
boolean b = m.matches();
如果只使用一次正则表达式,则如下的调用更加方便：
boolean b = Pattern.matches("a*b", "aaaaab");
*/
public class Demo01 {
public static void main(String args[]){
String exp="(你好)";
String str="朋友呀！你好，欢迎光临我的空间";
//将正则表达式用在本程序中
Pattern p=Pattern.compile(exp);
//将得到的模式用来创建匹配器
Matcher m=p.matcher(str);
//find()方法判断内容是否和模式匹配上
while(m.find()){
//group方法返回匹配上的字符串
System.out.println("匹配上的字符为："+m.group());
//返回匹配的开始索引和结束索引
int start=m.start();
int end=m.end();
//替换使用(你好-->hello)
StringBuffer sb=new StringBuffer();
sb.append(str.substring(0,start));
sb.append("hello");
sb.append(str.substring(end, str.length()));
System.out.println("替换后的结构为："+sb);
}
}
}
|
| 中文排序注意 |
java语言, 排序 |
中文排序要注意的问题 |
String[] strs = {"张三(Z)","李四(L)","王五(W)"};
//定义一个中文排序器
Comparator c = Collator.getInstance(Locale.CHINA);
//升序排列
Arrays.sort(strs,c);
|
| jsp中利用smartupload上传文件 |
|
|
注意事项：
1.将smartupload.jar包存放于WebRoot\WEB-INF\lib和F:\Tomcat 6.0\lib下。
2.将smartupload.jar引进项目：项目名右击—>build path——>external jar
3.在<@ path import="">中引进smart类
<%@ page language="java" import="java.util.*" pageEncoding="GBK"%>
<%@ page import="com.jspsmart.upload.*"%>//类地址是固定的，不知是为什么？
<html>
<head>
<title>My JSP 'smartupload_demo.jsp' starting page</title>
</head>
<body>
<%
SmartUpload smart=new SmartUpload();
smart.initialize(pageContext);
smart.upload();
smart.save("upload");
%>
</body>
</html>
|
| http IO |
java i/o |
通过Java HTTP连接将网络图片下载到本地 |
package imageView;
import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
/**
* @说明 从网络获取图片到本地
* @author 崔素强
* @version 1.0
* @since
*/
public class GetImage {
/**
* 测试
* @param args
*/
public static void main(String[] args) {
String url = "http://www.baidu.com/img/baidu_sylogo1.gif";
byte[] btImg = getImageFromNetByUrl(url);
if(null != btImg && btImg.length > 0){
System.out.println("读取到：" + btImg.length + " 字节");
String fileName = "百度.gif";
writeImageToDisk(btImg, fileName);
}else{
System.out.println("没有从该连接获得内容");
}
}
/**
* 将图片写入到磁盘
* @param img 图片数据流
* @param fileName 文件保存时的名称
*/
public static void writeImageToDisk(byte[] img, String fileName){
try {
File file = new File("C:\\" + fileName);
FileOutputStream fops = new FileOutputStream(file);
fops.write(img);
fops.flush();
fops.close();
System.out.println("图片已经写入到C盘");
} catch (Exception e) {
e.printStackTrace();
}
}
/**
* 根据地址获得数据的字节流
* @param strUrl 网络连接地址
* @return
*/
public static byte[] getImageFromNetByUrl(String strUrl){
try {
URL url = new URL(strUrl);
HttpURLConnection conn = (HttpURLConnection)url.openConnection();
conn.setRequestMethod("GET");
conn.setConnectTimeout(5 * 1000);
InputStream inStream = conn.getInputStream();//通过输入流获取图片数据
byte[] btImg = readInputStream(inStream);//得到图片的二进制数据
return btImg;
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
/**
* 从输入流中获取数据
* @param inStream 输入流
* @return
* @throws Exception
*/
public static byte[] readInputStream(InputStream inStream) throws Exception{
ByteArrayOutputStream outStream = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int len = 0;
while( (len=inStream.read(buffer)) != -1 ){
outStream.write(buffer, 0, len);
}
inStream.close();
return outStream.toByteArray();
}
}
|
| scanner的正则功能 |
java io |
|
package lianshou;
//scanner可以实现去掉空格的作用，实现正则表达式
import java.util.Scanner;
public class Example{
public static void main(String args[]) throws Exception{
Scanner sc=new Scanner(System.in);
int x=sc.nextInt();
int y=sc.nextInt();
System.out.print(x+y);//输入2 3
sc.close();
}
};
|
| 面向对象之继承2 |
java实战经典代码 |
|
package lianshou;
abstract class A{ // 是定义了一个抽象类
public A(){
System.out.println("A、抽象类中的构造方法。") ;
}
};
class B extends A{ // 继承抽象类，因为B是普通类，所以必须覆写全部抽象方法
public B(){
super() ;
System.out.println("B、子类中的构造方法。") ;
}
};
public class Example{
public static void main(String args[]){
B b = new B() ;
}
};
|
| 面向对象之继承1 |
java实战经典代码 |
|
package lianshou;
import java.io.*;
class person{
void print(){
System.out.println("person->print()");
}
public void fun(){
System.out.println("person->fun()");
}
};
class student extends person{
public void print(){
super.print();
System.out.println("student->print()");
}
}
public class Example{
public static void main(String args[]) {
person p=new student();
p.print();
p.fun();
}
}
|
| 数据库操作例子 |
jdbc |
|
package lianshou;
import java.sql.Connection ;
import java.sql.DriverManager ;
import java.sql.Statement ;
import java.sql.ResultSet ;
public class Example{
// 定义MySQL的数据库驱动程序
public static final String DBDRIVER = "org.gjt.mm.mysql.Driver" ;
// 定义MySQL数据库的连接地址
public static final String DBURL = "jdbc:mysql://localhost:3306/cheng" ;
// MySQL数据库的连接用户名
public static final String DBUSER = "root" ;
// MySQL数据库的连接密码
public static final String DBPASS = "346520" ;
public static void main(String args[]) throws Exception {
Connection conn = null ; // 数据库连接
Statement stmt = null ; // 数据库的操作对象
ResultSet rs = null ; // 保存查询结果
String sql = "SELECT id,age,name,dizhi FROM user" ;
Class.forName(DBDRIVER) ; // 加载驱动程序
conn = DriverManager.getConnection(DBURL,DBUSER,DBPASS) ;
stmt = conn.createStatement() ;
rs = stmt.executeQuery(sql) ;
while(rs.next()){ // 依次取出数据
int id = rs.getInt("id") ; // 取出id列的内容
int age = rs.getInt("age") ; // 取出age列的内容
String name = rs.getString("name") ; // 取出name列的内容
String dizhi = rs.getString("dizhi") ; // 取出name列的内容
System.out.print("编号：" + id + "；") ;
System.out.print("年龄：" + age + "；") ;
System.out.print("姓名：" + name + "；") ;
System.out.println("地址：" + dizhi + "；") ;
System.out.println("-----------------------") ;
}
rs.close() ;
stmt.close() ;
conn.close() ; // 数据库关闭
}
};
|
| 将信息以指定的格式存入文件 |
file |
Java IO 之字符集相关及文件合并 |
import java.io.* ;
public class EncodeDemo
{
public static void main(String args[]) throws Exception
{
OutputStream out = null ;
out = new FileOutputStream(new File("D:/FileTest/a.txt")) ;
String str = "Hello,World" ;
out.write(str.getBytes("GB2312")) ;
out.close() ;
}
};
|
| 将系统属性输出到指定流上 |
file |
Java IO 之字符集相关及文件合并 |
public class ShowPropertiesDemo
{
public static void main(String args[])
{
// 通过此代码观察一下当前JVM中设置的属性
System.getProperties().list(System.out) ;
}
}
|
| Servlet |
|
自学Servlet_3_response |
//更改response的码表,通知服务器用UTF-8码表去取response中的数据，然后写给客户机
response.setCharacterEncoding("UTF-8");
//通知浏览器以UTF-8码表打开回送的数据
//response.setHeader("content-type", "text/html;charset=UTF-8");
response.setContentType("text/html;charset=UTF-8");
String data = "中国";
PrintWriter writer = response.getWriter();
writer.write(data);
|
| Java中给数字补位 |
java语言 |
Java中给数字补位 |
int number = 1;
NumberFormat formatter = NumberFormat.getNumberInstance();
formatter.setMinimumIntegerDigits(4);
formatter.setGroupingUsed(false);
String s = formatter.format(number);
System.out.println(s);
|
| 选择排序 |
排序 |
|
package lianshou;
/**
* 选择排序法
*/
import java.util.Calendar;
public class Example{
public static void main(String[] args){
int len=10;
int[] a=new int[len];
for(int i=0;i<len;i++){
int t=(int)(Math.random()*10+1); //random产生的是小数
a[i]=t;
}
selectSort select=new selectSort();
Calendar cal=Calendar.getInstance();
System.out.println("排序前："+cal.getTime());
for(int i=0;i<a.length-1;i++){
System.out.println(a[i]);
}
select.sort(a);
cal=Calendar.getInstance();
System.out.println("排序后："+cal.getTime());
for(int i=0;i<a.length-1;i++){
System.out.println(a[i]);
}
}
}
class selectSort {
public void sort(int a[]){
int position=0;
for(int i=0;i<a.length;i++){
int j=i+1;
position=i;
int temp=a[i];
for(;j<a.length;j++) {
if(a[j]<temp){
temp=a[j];
position=j;
}
}
a[position]=a[i];
a[i]=temp;
}
}
}
|
| 冒泡排序 |
排序 |
|
package lianshou;
/**
* 冒泡排序法
*/
import java.util.Calendar;
public class Example {
public static void main(String[] args) {
// TODO Auto-generated method stub
int len=10;
int[] a=new int[len];
for(int i=0;i<len;i++) {
int t=(int)(Math.random()*10+1);
a[i]=t;
}
bubbleSort bub=new bubbleSort();
Calendar cal=Calendar.getInstance(); //计算出排序的时间
System.out.println("排序前："+cal.getTime());
for(int i=0;i<a.length-1;i++){
System.out.println(a[i]);
}
bub.Sort(a);
cal=Calendar.getInstance();
System.out.println("排序后："+cal.getTime());
for(int i=0;i<a.length-1;i++){
System.out.println(a[i]);
}
}
}
class bubbleSort{
public void Sort(int a[]){
int temp=0;
for(int i=0;i<a.length-1;i++){
for(int j=0;j<a.length-1-i;j++){ //a.length-1-i到a.length的数据已经排好序了；
if(a[j]>a[j+1]){
temp=a[j];
a[j]=a[j+1];
a[j+1]=temp;}
}
}
}
}
|
