使用groovy和java两种方式下载文件文件

groovy方式

def downloadTemplate = {
def appPath = servletContext.getRealPath("/").toString()
def file = new File(appPath + "template/" + params.fileName)
response.setHeader("Content-disposition", "attachment; filename=merTemplate.xls")
response.contentType = "application/x-rarx-rar-compressed"
response.setCharacterEncoding("utf-8")
response.outputStream << file.newInputStream()
}

java方式

def downloadTemplate = {
try {
def appPath = servletContext.getRealPath("/").toString()
def file = new File(appPath + "template/" + params.fileName)

if(file.length()>0){
response.setHeader("Content-disposition", "attachment; filename=merTemplate.xls")
response.contentType = "application/x-rarx-rar-compressed"
response.setCharacterEncoding("utf-8")
def out = response.getOutputStream()
InputStream is = new FileInputStream(file)
byte[] buffer = new byte[1024]
int i = -1
while ((i = is.read(buffer)) != -1){
out.write(buffer, 0, i)
}
out.flush()
out.close()
is.close()
}
}catch(Exception ex) {
ex.printStackTrace()
}
}

此为Grails项目中代码。

groovy方式应为使用其定义的<<方式，显得实现较为简单，但流的关闭不确定groovy是如何处理的

java方式就是我们比较熟悉了，有文件流的关闭，感觉比较条理清晰。

建议还是使用java这种方式来实现。