如何使用CFML生成图片缩略图文件?

2006-06-15 03:50:48 471 阅读 AI 写同款 · GEO 优化AI 选题数据监测一键分发 ›

基于51单片机的贪吃蛇游戏设计本科时候做的一个课程作业，自己打一个很简易的电路，比较有意思且易上手，故将之记录下来。（全套的仿真及代码，演示视频，课程报告以及PPT展示上传在CSDN下载区）一. 实验目的（1）通过对C51语言的理解，编写程序实现对贪吃蛇的有效控制；（2）通过对51单片机硬件的学习，学会运用面包板，独立按键、点阵屏等，完成对完整电路的搭建过程；（3）通过对Proteus仿真软件的学习，实现基于STC89C52单片机的8*8点阵贪吃蛇的硬件电路仿真。二. 实验介绍贪吃蛇是一款经典小游戏，其游戏的规则是：玩阅读详情

现做一网站，使用CFM，里面有图片显示，图片文件比较大。
想在上传的同时能够自动生成缩略图文件。
用ASP或者PHP可以找到资料，CFM找不到资料。
急求帮助。

...全文

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Dogfish 2006-06-16

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CFMX里，你可以把你写的Java Class方进去，然后在CFM里调用。

import com.sun.image.codec.jpeg.*;
import java.awt.*;
import java.awt.image.*;
import java.io.*;

/**
* Thumbnail.java (requires Java 1.2+)
* Load an image, scale it down and save it as a JPEG file.
* @author Marco Schmidt
*/
public class Thumbnail {
public static void main(String[] args) throws Exception {
if (args.length != 5) {
System.err.println("Usage: java Thumbnail INFILE " +
"OUTFILE WIDTH HEIGHT QUALITY");
System.exit(1);
}
// load image from INFILE
Image image = Toolkit.getDefaultToolkit().getImage(args[0]);
MediaTracker mediaTracker = new MediaTracker(new Container());
mediaTracker.addImage(image, 0);
mediaTracker.waitForID(0);
// determine thumbnail size from WIDTH and HEIGHT
int thumbWidth = Integer.parseInt(args[2]);
int thumbHeight = Integer.parseInt(args[3]);
double thumbRatio = (double)thumbWidth / (double)thumbHeight;
int imageWidth = image.getWidth(null);
int imageHeight = image.getHeight(null);
double imageRatio = (double)imageWidth / (double)imageHeight;
if (thumbRatio < imageRatio) {
thumbHeight = (int)(thumbWidth / imageRatio);
} else {
thumbWidth = (int)(thumbHeight * imageRatio);
}
// draw original image to thumbnail image object and
// scale it to the new size on-the-fly
BufferedImage thumbImage = new BufferedImage(thumbWidth,
thumbHeight, BufferedImage.TYPE_INT_RGB);
Graphics2D graphics2D = thumbImage.createGraphics();
graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR);
graphics2D.drawImage(image, 0, 0, thumbWidth, thumbHeight, null);
// save thumbnail image to OUTFILE
BufferedOutputStream out = new BufferedOutputStream(new
FileOutputStream(args[1]));
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(out);
JPEGEncodeParam param = encoder.
getDefaultJPEGEncodeParam(thumbImage);
int quality = Integer.parseInt(args[4]);
quality = Math.max(0, Math.min(quality, 100));
param.setQuality((float)quality / 100.0f, false);
encoder.setJPEGEncodeParam(param);
encoder.encode(thumbImage);
out.close();
System.out.println("Done.");
System.exit(0);
}
}

Dogfish 2006-06-16

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找Java的。可以使用。

huacha 2006-06-16

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http://www.wave12.com/web/SigCon.asp?bCate=41&sCateName=%B9%A6%C4%DC%BD%E9%C9%DC&ID=143&CateName=wsChart4.5(DLL)

Dogfish 2006-06-16

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Using CFObject For Java Integration
Question: I need to find out what exactly is required in order to utilize Java class files with the CFOBJECT tag. I really need to know where they need to be stored and what the different values should be within the Java section of the ColdFusion Administrator.
Charlie's answer:

First let me point out I have a page full of other resources on marrying cf and java. That info was written for the CF4.5 and 5 releases, as is this answer, but much of it still applies in CFMX.
Second, Guy Rish did a real good job with an article series in the CFDJ (www.coldfusionjournal.com) on incorporating Java and CF. Links to the articles are offered on that "marrying cf and java" page above.

As the questioner asks, the admin setup is indeed one of the keys. We're referring to the "JVM and Java Settings" in the Administrator.

There are two big kickers in getting this working (assuming, of course, one understands Java, and compiling classes, and classpaths, etc.)

Installing Java The first key to being able to run java class files in CF is to install a Java Virtual Machine (JVM) on the ColdFusion server box. The good news is that this is done automatically in CFMX. For those running CF 4.5 or 5, you need to install Java yourself. You can find one at http://java.sun.com/j2se/downloads.html. You will likely want to use the 1.3 or greater version. Setting the "Java Virtual Machine Path"

Next, those using 4.5 or 5 must set the admin field called "Java Virtual Machine path" after installing the JVM. (In CFMX, it's already filled in on installation of CFMX, set by default to [CFusionMX-home]/runtime/jre. You can skip to the next section.)

This "JVM Path" field prompt is a bit of a misnomer. It's indeed the location of the jvm, but in CF 4.5 and 5 it's the name of the file not just the location. So if your jvm.dll is located in D:\jdk1.3\jre\bin\classic\, then the value to put there is D:\jdk1.3\jre\bin\classic\jvm.dll (note the addition of jvm.dll). If you're running Unix or Linux, the filename is libjvm.so, according to wording on this screen in the CF 5 admininstrator.

If in Windows you don't know where your jvm.dll is, just use the Windows "file find" feature (or whatever os tool you have) to search your hard drive for jvm.dll. There may be a few. Any will do, typically, though you may want to check the version and be sure to use a recent JVM. Go to the DOS command line and change to the directory containing the jvm.dll. Use the java -version command to determine the version.

Setting the "Classpath" in the CF Administrator

Then the second key, if you then want to execute your own Java classes, is pointing the "class path" field in the CF administrator to wherever you have java class (or .jar) files. Let's say you store some code in c:\myjavaclasses. You'd want to add that path in the "class path" field. You can enter multiple directories, so if you're pointing to some classes belonging to another application, put that path there. Seperate multiple directories with a semi-colon in CF 4.5 and 5, and with commas in CFMX. If you change the class path field, you need to restart CF.

Setting the "CFX Jar Path" (in CF 4.5 or 5)

The last important field is the "cfx jar path" (though some of the other fields are important in certain implementations of java on certain os's). This field no longer exists in the CFMX admin. Even in CF 4.5 or 5, you don't really need to worry about the cfx jar path unless you're using cfx java custom tags.

CFX custom tags can integrate with CF by being able to read/write CF variables, queries, etc. See more on that in Chapter 18 of the "Developing Web Apps" book in CF 4.5, Chaper 21 in the "Developing ColdFusion Applications" book in CF5, or Chapter 12 in "Developing ColdFusionMX Applications with CFML" in CFMX.

But if one is doing cfx's, then in CF 4.5 or 5 the "cfx jar path" should point to the location of CF's built-in cfx.jar (which includes the libraries for doing this sort of thing). By default, it's in the cfusion\java\classes directory where CF is installed. Put the full drive and path in here.

Calling Your Java Classes

Now, calling a class with CFOBJECT is pretty simple. You just use:

<CFobject action="CREATE" type="JAVA" name="varname" class="classname">

where classname is the name of the class you want to run, and varname is the name of the variable which will hold the reference to the object. If you know the names of the object's methods and properties, you can refer to them, such as:

<CFset x = varname.method(attribute)>

where method is the name of some method in the object (java class) and attribute is something you may want to pass to that method.

Or if you wanted to refer to a property, you could do so as:

<CFoutput>#varname.property#</cfoutput>

If you wanted a demonstrable example, here is some simple java code that takes in a score and returns a grade:

public class grades {

public static char letterGrade(int numGrade) {

// Returns the letter grade corresponding to
// the numerical grade, numGrade.

if (numGrade >= 91)
return 'A'; // 90 or above gets an A
else if (numGrade >= 80)
return 'B'; // 80 to 89 gets a B
else if (numGrade >= 65)
return 'C'; // 65 to 79 gets a C
else if (numGrade >= 50)
return 'D'; // 50 to 64 gets a D
else
return 'F'; // anything else gets an F

} // end of function letterGrade()

}

If you put this in a directory pointed to on the the "classpath"you set above, and compile it successfully (I'll have to leave that step to your finding out more), you should be able to call it in CF:

<CFobject action="CREATE" type="JAVA" name="x" class="grades"> <CFset ret = x.letterGrade(90)> <CFoutput>#chr(ret)#</cfoutput>

Restarting the Server on Change of Classes

Once you've compiled a class and run it via CFOBJECT, you won't see any changes made in a recompilation of that object until the CF server is restarted.

However, CF 5 did add a "Dynamic Class Load Path" field to the administrator. If you specify a directory there, then CF 5 should detect a change to a class and use that on the next instantiation of an object in that class.

In CFMX, the field is no longer there, but you can instead tell CFMX to reload classes by changing the file [cfmx_home]\wwwroot\WEB-INF\jrun-web.xml, adding the following line within the existing <jrun-web-app> element: <reload>TRUE</reload> Restart the server. CFMX will now reload classes from [cfmx_home]\wwwroot\WEB-INF\classes as well as classes in jar/zip archives in [cfmx_home]\wwwroot\WEB-INF\lib. Note: The [cfmx_home]\wwwroot\WEB-INF\classes directory must contain class files only, not class archives. Java class archives belong under the [cfmx_home]\wwwroot\WEB-INF\lib directory

Of course, if one is calling pre-built classes or using home-grown ones in production where changes aren't frequent, the concern over being able to dynamically load changed classes is not important. Indeed, it would generally be unwise from a performance perspective to set up dynamic loading in production.

Hope that's all helpful.

如何使用CFML生成图片缩略图文件?

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