REST 图片流

写了个Spring rest 风格的 图片加载。

package cn.tang.demo.controller.image;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.RequestParam;

@Controller
@RequestMapping(value = "/image/")
public class ImageCacheController {
	
		// for restful http://localhost:8888/rest/image/load?imageName=a.jpg
		@RequestMapping(value = "/load", method = RequestMethod.GET)
		public void imageLoad(@RequestParam(value = "imageName", required = true) String imageName, HttpServletRequest request, HttpServletResponse response)
				throws IOException {
			File f = new File("c://"+imageName);
			if (!f.exists()) {
				return;
			}
			FileInputStream fis = new FileInputStream(f);
			byte[] buffer = new byte[1024];
			int len =0;
			try {
				response.setHeader("Content-Type", "image/jpg;charset=UTF-8");
				ServletOutputStream outputStream = response.getOutputStream();
				
				while ((len=fis.read(buffer)) > 0) {
					outputStream.write(buffer, 0, len);
				}
				outputStream.flush();
				
			} finally {
				fis.close();
			}
			
		}

	// for restful http://localhost:8888/rest/image/a.jpg
	@RequestMapping(value = "/{name:\\S*\\.?\\S+}", method = RequestMethod.GET)
	public void helloMan(@PathVariable String imageName, HttpServletRequest request, HttpServletResponse response)
			throws IOException {
		File f = new File("c://"+imageName);
		if (!f.exists()) {
			return;
		}
		FileInputStream fis = new FileInputStream(f);
		byte[] buffer = new byte[1024];
		int len =0;
		try {
			response.setHeader("Content-Type", "image/jpg;charset=UTF-8");
			ServletOutputStream outputStream = response.getOutputStream();
			
			while ((len=fis.read(buffer)) > 0) {
				outputStream.write(buffer, 0, len);
			}
			outputStream.flush();
			
		} finally {
			fis.close();
		}
		
	}

}

   这个是最基本的图片获取方式，我们可以把图片放入缓存中，然后通过读缓存而不是读文件来获取图片。