index.jsp

J2EE独立开发制作

<%@ page language="java" contentType="text/html;charset=GB2312"%>

<%@ page import="java.io.OutputStream" %>
<%@ page import="java.awt.image.BufferedImage" %>
<%@ page import="java.awt.*" %>
<%@ page import="com.sun.image.codec.jpeg.*" %> 

<%@ include file = "graphBG.jsp"%>

<% 

//Data arrays
String datanames[] = {"Apples", "Oranges", "Peaches", "Lemons", "Grapefruit"};

int datavalues[] = {11, 62, 33, 102, 50};

//current y position
int y_pos = 0;				

//y offset to cater for header space
int headerOffset = 50;  		

//inner padding to make sure bars never touch the outer border
int innerOffset = 20;			

//height of bar, text and total
int barHeight	= 10;
int textHeight	= 20;
int displayHeight = barHeight + textHeight;

//Color used for the bars
Color barColor = new Color(153,19,19);

//Set the graph's outer width
int WIDTH  = 300;		

//Set the graph's outer height
int HEIGHT = (datavalues.length * displayHeight) + headerOffset + innerOffset;

//Width of the graphable area
int innerWIDTH = WIDTH - (innerOffset * 2);	

//Calculate average
int average = 0;
for(int i=0; i<datavalues.length; i++)
{
	average += datavalues[i];
}
average = average / datavalues.length;

//Calculate maximum
int maximum = 0;
for(int i=0; i<datavalues.length; i++)
{
	if(datavalues[i] > maximum)
	{
		maximum = datavalues[i];
	}
}




///////////////////////////////////////////////////////////////////////////////////////
//Draw Graph Background and Header:
///////////////////////////////////////////////////////////////////////////////////////

response.setContentType("image/jpeg");
BufferedImage bi = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
Graphics2D biContext = bi.createGraphics();
graphBG gr = new graphBG();
gr.draw(biContext, WIDTH, HEIGHT, "Farm Produce", "Overall Average: " + average);



/////////////////////////////////////////////////////////////////////////////////////
//Draw data onto the graph:
/////////////////////////////////////////////////////////////////////////////////////


//Loop through & draw the bars

for(int i=0; i<datavalues.length; i++)
{
	int currentValue = datavalues[i];

	//Set y position for bar
	y_pos = i * displayHeight + headerOffset;
	
	//Set bar width
	int barWidth = (innerWIDTH * currentValue) / maximum;

	//Display the current value
	String display = datanames[i] + " (" + currentValue + ")";
	biContext.setColor(Color.black);
	biContext.drawString(display, 20, y_pos);

	//Set dimensions of the bar
	biContext.setColor(barColor);
	Dimension bar = new Dimension(barWidth , barHeight);
	Dimension barBorder = new Dimension(barWidth - 3 , barHeight - 3);
	Rectangle barRect = new Rectangle(bar);
	Rectangle barRectBorder = new Rectangle(barBorder);
	
	//Draw bar and border:		
	barRect.setLocation(21, 5 + y_pos);
	barRectBorder.setLocation(22, 6 + y_pos);
	biContext.setColor(barColor);
	biContext.fill(barRect);
	biContext.setColor(Color.white);
	biContext.draw(barRectBorder);
}



/////////////////////////////////////////////////////////////////////////////////////
//Display the graph
/////////////////////////////////////////////////////////////////////////////////////

//Encode:
OutputStream output = response.getOutputStream();
JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(output);
encoder.encode(bi);
output.close();

%>