项目一个需求，展示横向柱状图，自己动手封装了一个生成柱状图的工具类，效果图如下：
下面上代码：
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.math.BigDecimal;
import java.util.Arrays;
import java.util.List;
import javax.imageio.ImageIO;
import javax.servlet.http.HttpServletRequest;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGEncodeParam;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
import com.wangyun.vo.Style;
/**
* @ClassName: 柱状图工具类
* @Description: 根据设置各个参数，生成柱状图
* @author: wangyun
* @date: 2018-5-4 下午3:00:20
*/
public class PlotUtils {
/**
* 生成图片
* @param names 城市名称
* @param dls 对应数值
* @param objList RGB 值
* @param dl 平均值
* @param cutValue 分割线最大值
* @throws FileNotFoundException
*/
public static String CreatePicture(String[] names,double[] dls,List<Style> objList ,double dl,double cutValue,String name,HttpServletRequest request ) throws FileNotFoundException{
String proute = null;
//图片宽度
int width = 1000;
//左侧标题栏宽度
int lwidth = 200;
//图片高度
int high = (names.length+1)*40;
//求出负数最大值
double dlss [] =new double[dls.length];
//解释：主要是为了防止指向同一个地址
for (int i = 0; i < dls.length; i++) {
dlss[i]=dls[i];
}
Arrays.sort(dlss);//从小到大
double fudl =0.00 ;
if(dlss[0]<0){
fudl =dlss[0];
cutValue=-dlss[0]*5;
}else{
cutValue=dlss[dlss.length-1]+dl;
}
// 得到图片缓存区 宽度 高度 图片类别
BufferedImage bi = new BufferedImage(width, high, BufferedImage.TYPE_INT_RGB);
// 得到它的绘制环境（这张图片的笔）
Graphics2D g2 = (Graphics2D)bi.getGraphics();
// 设置左侧画布颜色
g2.setColor(new Color(Integer.valueOf(objList.get(0).getR()), Integer.valueOf(objList.get(0).getG()), Integer.valueOf(objList.get(0).getB())));
// 填充整张图片(其实就是设置背景颜色)int x, int y, int width, int height
g2.fillRect(0, 0, lwidth, high);
//设置左侧标题框
int k=0;
for (int i = 0; i < names.length; i++) {
// 设置字体
g2.setFont(new Font("宋体", Font.BOLD, 26));
//设置城市名称字体颜色
g2.setColor(new Color(Integer.valueOf(objList.get(1).getR()), Integer.valueOf(objList.get(1).getG()), Integer.valueOf(objList.get(1).getB())));
// 抗锯齿
g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
g2.drawString(" "+sub_Str(names[i]), 30, 40+i*40);
if(k>=0&&k<5){
g2.setColor(new Color(Integer.valueOf(objList.get(2).getR()), Integer.valueOf(objList.get(2).getG()), Integer.valueOf(objList.get(2).getB())));
k++;
}else{
g2.setColor(new Color(Integer.valueOf(objList.get(3).getR()), Integer.valueOf(objList.get(3).getG()), Integer.valueOf(objList.get(3).getB())));
k++;
if(k>9){
k=0;
}
}
g2.fillRoundRect(5,20+i*40,26,26, 0, 0);
//序号颜色
g2.setColor(new Color(Integer.valueOf(objList.get(4).getR()), Integer.valueOf(objList.get(4).getG()), Integer.valueOf(objList.get(4).getB())));
g2.setFont(new Font("宋体", Font.BOLD, 26));
if(i>=0&&i<9){
g2.drawString(""+(i+1)+" ", 5, 40+i*40);
}else{
g2.drawString(i+1+" ", 5, 40+i*40);
}
}
//设置右侧画布颜色
g2.setColor(new Color(Integer.valueOf(objList.get(5).getR()), Integer.valueOf(objList.get(5).getG()), Integer.valueOf(objList.get(5).getB())));
// 填充整张图片(其实就是设置背景颜色)int x, int y, int width, int height
g2.fillRect(lwidth, 0, width, high);
//设置分割线颜色
g2.setColor(new Color(Integer.valueOf(objList.get(6).getR()), Integer.valueOf(objList.get(6).getG()), Integer.valueOf(objList.get(6).getB())));
for (int i = 0; i <5; i++) {
g2.drawLine(lwidth+(width-lwidth)/5*i,0, lwidth+(width-lwidth)/5*i,high);
}
//设置分割线数字颜色
g2.setFont(new Font("宋体", Font.BOLD, 20));
g2.setColor(new Color(Integer.valueOf(objList.get(7).getR()), Integer.valueOf(objList.get(7).getG()), Integer.valueOf(objList.get(7).getB())));
for (int i = 0; i <5; i++) {
g2.drawString(""+new BigDecimal((cutValue/5)*i+fudl).setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue(), lwidth+(width-lwidth)/5*i, 15);//设置分割线数值
}
//设置柱体
int p = 0;
for (int i = 0; i < dls.length; i++) {//int x, int y, int width, int height, int arcWidth, int arcHeight
//设置柱体颜色
g2.setColor(new Color(Integer.valueOf(objList.get(8).getR()), Integer.valueOf(objList.get(8).getG()), Integer.valueOf(objList.get(8).getB())));
if(dls[i]>0){
if(dls[i]>cutValue){
if(dlss[0]<0){
g2.fillRoundRect(lwidth-(int)(fudl*(width-lwidth)/cutValue),20+i*40,(width-lwidth)*3/5,26, 0, 0);
g2.fillRoundRect(lwidth-(int)(fudl*(width-lwidth)/cutValue)+(width-lwidth)*3/5+10,20+i*40,90,26, 0, 0);
}else{
g2.fillRoundRect(lwidth-(int)(fudl*(width-lwidth)/cutValue),20+i*40,(width-lwidth)*4/5,26, 0, 0);
g2.fillRoundRect(lwidth-(int)(fudl*(width-lwidth)/cutValue)+(width-lwidth)*4/5+10,20+i*40,90,26, 0, 0);
}
}else{
g2.fillRoundRect(lwidth-(int)(fudl*(width-lwidth)/cutValue),20+i*40,(int)(dls[i]*(width-lwidth)/cutValue),26, 0, 0);
}
}else{
g2.fillRoundRect(lwidth-(int)((fudl-dls[i])*(width-lwidth)/cutValue),20+i*40,(int)(-dls[i]*(width-lwidth)/cutValue),26, 0, 0);
}
if(p==0){
if(dls[i]>dl&&dls[i+1]<dl){
//绘制平均线
g2.setColor(new Color(Integer.valueOf(objList.get(9).getR()), Integer.valueOf(objList.get(9).getG()), Integer.valueOf(objList.get(9).getB()))); //int x1, int y1, int x2, int y2
g2.drawLine( lwidth,53+i*40, width,50+i*40);
//绘制平均线数值
g2.setColor(new Color(Integer.valueOf(objList.get(10).getR()), Integer.valueOf(objList.get(10).getG()), Integer.valueOf(objList.get(10).getB()))); //int x1, int y1, int x2, int y2
g2.setFont(new Font("宋体", Font.BOLD, 20));
g2.drawString(new BigDecimal(dl).setScale(2, BigDecimal.ROUND_HALF_UP).doubleValue()+"", width-100, 80+i*40);
p++;
}
}
}
//设置柱体数值
for (int i = 0; i < dls.length; i++) {
// 设置字体
g2.setColor(new Color(Integer.valueOf(objList.get(11).getR()), Integer.valueOf(objList.get(11).getG()), Integer.valueOf(objList.get(11).getB())));
g2.setFont(new Font("宋体", Font.BOLD, 20));
if(dls[i]>0){
if(dls[i]>cutValue){
if(dlss[0]<0){
g2.drawString(""+dls[i],lwidth-(int)(fudl*(width-lwidth)/cutValue)+(width-lwidth)*3/5+100, 40+i*40);
}else{
g2.drawString(""+dls[i],lwidth-(int)(fudl*(width-lwidth)/cutValue)+(width-lwidth)*4/5+100, 40+i*40);
}
}else{
g2.drawString(""+dls[i],lwidth-(int)((fudl-dls[i])*(width-lwidth)/cutValue), 40+i*40);
}
}else{
g2.drawString(""+dls[i],lwidth-(int)(fudl*(width-lwidth)/cutValue), 40+i*40);
}
}
//绘制图片右下边框线
//设置粗度
g2.setStroke(new BasicStroke(8.0f));
//设置颜色
g2.setColor(new Color(Integer.valueOf(objList.get(12).getR()), Integer.valueOf(objList.get(12).getG()), Integer.valueOf(objList.get(12).getB()))); //int x1, int y1, int x2, int y2
g2.drawLine( width,0,width,high);//绘制右黑色线
g2.drawLine( 0,high,width,high);//绘制下黑色线
String path =request.getSession().getServletContext().getRealPath("/upload/");
String realPath="/upload/";
try {
File dir = new File(path,name+".jpg");
ImageIO.write(bi, "JPEG", dir);
handleDpi(dir, 300, 300);
g2.dispose();
bi=null;
System.gc();
} catch (IOException e) {
e.printStackTrace();
}
proute = realPath+name+".jpg";
return proute;
}
/**
* 根据输入的字符串判断字符长度，添加相应空格
* @param cityName
* @return
*/
public static String sub_Str(String cityName){
String ss=null;
int count =0;
char[] c = cityName.toCharArray();
for(int i = 0; i < c.length; i ++)
{
String len = Integer.toBinaryString(c[i]);
if(len.length() > 8)
count ++;
}
if(count==2){
ss=cityName.substring(0, 1)+" "+" "+" "+cityName.substring(1);
}else if(count==3){
ss=cityName.substring(0, 1)+" "+cityName.substring(1,2)+" "+cityName.substring(2,3);
}else if(count==4){
ss=cityName.substring(0, 1)+" "+cityName.substring(1,2)+""+cityName.substring(2,3)+" "+cityName.substring(3,4);
}else if(count==5){
ss=cityName;
}else{
ss="11111111111";
}
return ss;
}
/**
* 改变图片DPI
*
* @param file
* @param xDensity
* @param yDensity
*/
public static void handleDpi(File file, int xDensity, int yDensity) {
try {
BufferedImage image = ImageIO.read(file);
JPEGImageEncoder jpegEncoder = JPEGCodec.createJPEGEncoder(new FileOutputStream(file));
JPEGEncodeParam jpegEncodeParam = jpegEncoder.getDefaultJPEGEncodeParam(image);
jpegEncodeParam.setDensityUnit(JPEGEncodeParam.DENSITY_UNIT_DOTS_INCH);
jpegEncoder.setJPEGEncodeParam(jpegEncodeParam);
jpegEncodeParam.setQuality(0.75f, false);
jpegEncodeParam.setXDensity(xDensity);
jpegEncodeParam.setYDensity(yDensity);
jpegEncoder.encode(image, jpegEncodeParam);
image.flush();
} catch (IOException e) {
e.printStackTrace();
}
}
}
过程遇到的问题总结：
1.数据有正负，画图时需要做一些判断。
2.有些数据比其他数据要大很多，需要做折断。
3.Graphics2D和BufferedImage最后关闭的问题，如果不关闭，在程序运行是不可以访问图片，我的解决办法是：
问题解决，不足之处请多多指点。