java snapshot

java snapshot是什么？讓我們一起來(lái)了解一下吧！?

首先java snapshot是指Java maven程序中的快照。而快照是一個(gè)非常特別的版本，設(shè)定了某個(gè)現(xiàn)在的開(kāi)發(fā)進(jìn)度的副本。與一般的版本不同，maven開(kāi)源項(xiàng)目每次會(huì)隨著代碼的更新而發(fā)布快照。

SNAPSHOT作用：

1.標(biāo)識(shí)jar是一個(gè)不穩(wěn)定的文件項(xiàng)目，起標(biāo)識(shí)版本的作用。

2.運(yùn)用SNAPSHOT之后，maven會(huì)常常去私服或是中央倉(cāng)庫(kù)中拉取最新的這個(gè)jar的版本；而沒(méi)有SNAPSHOT的jar，則會(huì)從本地倉(cāng)庫(kù)中查找，本地不存在，才去中央倉(cāng)庫(kù)中拉取。

3.更新頻率：需要在pom.xml文件中進(jìn)行配置。

java實(shí)現(xiàn)網(wǎng)頁(yè)快照需要的具體代碼如下：

???????
import?java.awt.Graphics2D;
import?java.awt.RenderingHints;
import?java.awt.geom.AffineTransform;
import?java.awt.image.BufferedImage;
import?java.awt.image.ColorModel;
import?java.awt.image.WritableRaster;
import?java.io.*;
import?javax.imageio.*;
import?javax.swing.*;

/**
?*?HTML2JPG,HTML頁(yè)面轉(zhuǎn)圖片的實(shí)現(xiàn)方法。
?*?
?*?@author?老紫竹(Java世紀(jì)網(wǎng),java2000.net)
?*/
public?class?Test?extends?JFrame?{

??public?Test(String?url,?File?file)?throws?Exception?{
????JEditorPane?editorPane?=?new?JEditorPane();
????editorPane.setEditable(false);
????editorPane.setPage(url);
????JScrollPane?jsp?=?new?JScrollPane(editorPane);
????getContentPane().add(jsp);
????this.setLocation(0,?0);
????this.setVisible(true);?//?如果這里不設(shè)置可見(jiàn)，則里面的圖片等無(wú)法截取
????
????//?如果不延時(shí)，則圖片等可能沒(méi)有時(shí)間下載顯示
????//?具體的秒數(shù)需要根據(jù)網(wǎng)速等調(diào)整
????Thread.sleep(5?*?1000);

????setSize(10000,?10000);

????pack();
????//?BufferedImage?image?=?new?BufferedImage(editorPane.getWidth(),
????//?editorPane.getHeight(),?BufferedImage.TYPE_INT_RGB);
????BufferedImage?image?=?new?BufferedImage(editorPane.getWidth(),?editorPane.getHeight(),
????????BufferedImage.TYPE_INT_RGB);
????Graphics2D?graphics2D?=?image.createGraphics();
????editorPane.paint(graphics2D);
????
????BufferedImage?image1?=?resize(image,?600,?400);

????ImageIO.write(image1,?"jpg",?file);
????dispose();
??}

??public?static?void?main(String[]?args)?throws?Exception?{
????new?Test("http://www.google.cn",?new?File("d:/file.jpg"));
??}

??public?static?BufferedImage?resize(BufferedImage?source,?int?targetW,?int?targetH)?{
????//?targetW，targetH分別表示目標(biāo)長(zhǎng)和寬
????int?type?=?source.getType();
????BufferedImage?target?=?null;
????double?sx?=?(double)?targetW?/?source.getWidth();
????double?sy?=?(double)?targetH?/?source.getHeight();
????//?這里想實(shí)現(xiàn)在targetW，targetH范圍內(nèi)實(shí)現(xiàn)等比縮放。如果不需要等比縮放
????//?則將下面的if?else語(yǔ)句注釋即可
????if?(sx?>?sy)?{
??????sx?=?sy;
??????targetW?=?(int)?(sx?*?source.getWidth());
??????//?}?else?{
??????//?sy?=?sx;
??????//?targetH?=?(int)?(sy?*?source.getHeight());
????}
????if?(type?==?BufferedImage.TYPE_CUSTOM)?{?//?handmade
??????ColorModel?cm?=?source.getColorModel();
??????WritableRaster?raster?=?cm.createCompatibleWritableRaster(targetW,?targetH);
??????boolean?alphaPremultiplied?=?cm.isAlphaPremultiplied();
??????target?=?new?BufferedImage(cm,?raster,?alphaPremultiplied,?null);
????}?else
??????target?=?new?BufferedImage(targetW,?targetH,?type);
????Graphics2D?g?=?target.createGraphics();
????//?smoother?than?exlax:
????g.setRenderingHint(RenderingHints.KEY_RENDERING,?RenderingHints.VALUE_RENDER_QUALITY);
????g.drawRenderedImage(source,?AffineTransform.getScaleInstance(sx,?sy));
????g.dispose();
????return?target;
??}
}

以上就是小編今天的分享了，希望可以幫助到大家。