我有一个 AJAX POST 请求以 JSON 数组的形式取回数据。 我想将收到的 JSON 数据转换为 Excel 文件（不是 CSV）以供下载（单击按钮），请帮助。 JSON 数据的每个 JSON 行可能具有空白值和缺失字段。
我在客户端使用Javascript尝试了这个，但没有在Java服务器端尝试过，在这种情况下，我将不得不在AJAX End-Point方法中使用@Produces(MediaType.MULTIPART_FORM_DATA)，这是我可以尝试的方法，但认为它很复杂。
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"
}
]
这是一种从 WebService（Resteasy 实现）生成 excel 的方法，经过测试且完全有效：
@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启动后的文件输入：
@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...
@Blackjack，下面是代码...
1) 单击按钮即可调用函数。这具有将 Excel 文件传递到 REST 端点函数的 AJAX 调用：
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();
}