我有一个AJAX POST请求以JSON数组的形式提取数据。 我想将收到的JSON数据转换为Excel文件（非CSV）进行下载（按下按钮），请帮忙。 JSON数据可能包含每个JSON行的空值和缺少的字段。
我在客户端使用Javascript但在Java服务器端没有尝试过这种情况，在这种情况下，我将不得不在AJAX端点方法中使用@Produces（MediaType.MULTIPART_FORM_DATA），这是我可以尝试但我认为它的复杂性
a）AJAX请求代码：
function fileUploadFunction() {
var file = $('input[name="file"').get(0).files[0];
var formData = new FormData();
if(file.name != null) {
document.getElementById("btnUpload").disabled = false;
formData.append('file', file);
$.ajax({
url : "<%=request.getContextPath()%>/rest/upload/upload",
type : "POST",
data : formData,
cache : false,
contentType : false,
processData : false,
success : function(response) {
//Store result in Session and Enable Download button
var cacheString = JSON.stringify(response, null, 2);
console.log("-----------------> cacheString is: " + cacheString);
if(cacheString != null && cacheString != "[]") {
document.getElementById("download").disabled = false;
}
var sessionresponse = sessionStorage.setItem("i98779", cacheString);
console.log("response is: " + response);
console.log("cacheString is: " + cacheString);
excelDownload(cacheString);
//createTable(response);
//https://stackoverflow.com/questions/47330520/how-to-export-json-object-into-excel-using-javascript-or-jquery
},
error : function(jqXHR, textStatus, errorThrown) {
console.log(errorThrown);
alert("Error: " + errorThrown);
}
});//ajax ends
}//if ends
}//Function ends
b）从AJAX POST请求收到的JSON示例数据：
[
{
"entityid":2,
"firstname":"George",
"lastname":"Bush",
"ssn":"",
"city":"Houston",
"state":"TX",
"country":"USA",
"zipcode":""
},
{
"entityid": 8,
"firstname": "Jim",
"lastname": "Macron",
"ssn": "888-88-8888",
"city": "Paris",
"state": "NY",
"country": "France",
"zipcode": "T789J"
},
{
"entityid": 11,
"firstname": "Angela",
"lastname": "Merkel",
"city": "Saxony",
"zipcode": ""
},
{
"entityid": 7,
"firstname": "Donald",
"lastname": "Trump",
"ssn": "777-77-7777",
"city": "Washington D.C.",
"state": "DC",
"country": "USA",
"zipcode": "70000"
}
]
答案 0 :(得分：0)
这是一种从WebService（Resteasy Implementation）生成excel的方法，经过测试并完全正常工作：
@POST
@Path("/excelpost")
@Produces(MediaType.APPLICATION_OCTET_STREAM)
public Response downloadFilePost( ) throws IOException {
XSSFWorkbook workbook = new XSSFWorkbook();
XSSFSheet sheet = workbook.createSheet("Datatypes in Java");
Object[][] datatypes = {
{"Datatype", "Type", "Size(in bytes)"},
{"int", "Primitive", 2},
{"float", "Primitive", 4},
{"double", "Primitive", 8},
{"char", "Primitive", 1},
{"String", "Non-Primitive", "No fixed size"}
};
int rowNum = 0;
System.out.println("Creating excel");
for (Object[] datatype : datatypes) {
Row row = sheet.createRow(rowNum++);
int colNum = 0;
for (Object field : datatype) {
Cell cell = row.createCell(colNum++);
if (field instanceof String) {
cell.setCellValue((String) field);
} else if (field instanceof Integer) {
cell.setCellValue((Integer) field);
}
}
}
ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
workbook.write(outputStream);
workbook.close();
return Response.status(200).header("Access-Control-Allow-Origin", "*")
.header("Content-Disposition", "attachment;filename='fileName.xlsx'")
.header("Access-Control-Allow-Headers", "origin, content-type, accept, authorization")
.header("Access-Control-Allow-Credentials", "true")
.header("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS, HEAD")
.header("Access-Control-Max-Age", "1209600").entity( new ByteArrayInputStream(outputStream.toByteArray() )).build();
}
这是管理Excel文件的maven依赖：
<dependency>
<groupId>org.apache.poi</groupId>
<artifactId>poi</artifactId>
<version>3.17</version>
</dependency>
您可以轻松添加适当的注释和网络参数来管理服务的起始帖子中的文件输入：
@POST
@Path("/excelpost")
@Consumes(MediaType.MULTIPART_FORM_DATA)
@Produces(MediaType.APPLICATION_OCTET_STREAM)
public Response downloadFilePost(MultipartFormDataInput input)
.......
如果有帮助，请告诉我......
答案 1 :(得分：0)
@Blackjack，下面是代码......
1）点击按钮时调用功能。这有AJAX调用，它将Excel文件传递给REST端点函数：
function fileUploadFunction() {
var file = $('input[name="file"').get(0).files[0];
var formData = new FormData();
if(file.name != null) {
document.getElementById("btnUpload").disabled = false;
formData.append('file', file);
$.ajax({
url : "<%=request.getContextPath()%>/rest/upload/bulkSearch",
type : "POST",
data : formData,
cache : false,
contentType : false,
processData : false,
success : function(response) {
//Store result in Session and Enable Download button
var cacheString = JSON.stringify(response, null, 2);
console.log("-----------------> cacheString is: " + cacheString);
if(cacheString != null && cacheString != "[]") {
document.getElementById("download").disabled = false;
}
var sessionresponse = sessionStorage.setItem("i98779", cacheString);
console.log("response is: " + response);
console.log("cacheString is: " + cacheString);
//excelDownload(cacheString);
//createTable(response);
//https://stackoverflow.com/questions/47330520/how-to-export-json-object-into-excel-using-javascript-or-jquery
},
error : function(jqXHR, textStatus, errorThrown) {
console.log(errorThrown);
alert("Error: " + errorThrown);
}
});//ajax ends
}//if ends
}//Function ends
2）REST端点功能：
@POST
@Consumes(MediaType.MULTIPART_FORM_DATA)
@Produces(MediaType.APPLICATION_OCTET_STREAM)
@Path("/bulkSearch")
public Response bulkSearch(
@FormDataParam("file") InputStream uploadedInputStream,
@FormDataParam("file") FormDataContentDisposition fileDetail) throws IOException {
System.out.println("Entered uploadFile method");
System.out.println("uploadedInputStream is: " + uploadedInputStream);
System.out.println("fileDetail is: " + fileDetail.toString());
String returnJSON = null;
List<User> usersList = null;
ObjectMapper uploadMapper = new ObjectMapper();
//System.out.println("File name is: " + fileDetail.getFileName());
//System.out.println("File size is : " + fileDetail.getSize());
//System.out.println("File size is : " + fileDetail.getType());
// check if all form parameters are provided
if (uploadedInputStream == null || fileDetail == null)
return Response.status(400).entity("Invalid form data").build();
System.out.println("Checked Input file is ok");
System.out.println("----------------------------------------------------------------");
XSSFWorkbook workbook = new XSSFWorkbook();
XSSFSheet sheet = workbook.createSheet("Datatypes in Java");
Object[][] datatypes = {
{"Datatype", "Type", "Size(in bytes)"},
{"int", "Primitive", 2},
{"float", "Primitive", 4},
{"double", "Primitive", 8},
{"char", "Primitive", 1},
{"String", "Non-Primitive", "No fixed size"}
};
int rowNum = 0;
System.out.println("Creating excel");
for (Object[] datatype : datatypes) {
Row row = sheet.createRow(rowNum++);
int colNum = 0;
for (Object field : datatype) {
org.apache.poi.ss.usermodel.Cell cell = row.createCell(colNum++);
if (field instanceof String) {
cell.setCellValue((String) field);
} else if (field instanceof Integer) {
cell.setCellValue((Integer) field);
}
}
}
System.out.println("For loop done");
ByteArrayOutputStream outputStream = new ByteArrayOutputStream(); //-----> no reference to excel cells here
System.out.println("outputstream done");
workbook.write(outputStream);
System.out.println("workbook.write done");
workbook.close();
System.out.println("workbook closed");
return Response.status(200).header("Access-Control-Allow-Origin", "*")
.header("Content-Disposition", "attachment;filename='fileName.xlsx'")
.header("Access-Control-Allow-Headers", "origin, content-type, accept, authorization")
.header("Access-Control-Allow-Credentials", "true")
.header("Access-Control-Allow-Methods", "GET, POST, PUT, DELETE, OPTIONS, HEAD")
.header("Access-Control-Max-Age", "1209600").entity( new ByteArrayInputStream(outputStream.toByteArray() )).build();
}