使用POI XWPF生成Word文档，引入POI:

<dependency>
    <groupId>org.apache.poi</groupId>
    <artifactId>poi-ooxml</artifactId>
    <version>4.1.0</version>
</dependency>

项目中经常从Word模板生成文档，下面示例演示了替换文档内容的方法。模版中要替换的内容以${}标识，调用XWPFRun.setText()方法更新文档。

package org.iata.caims.util;

import org.apache.poi.xwpf.usermodel.XWPFDocument;
import org.apache.poi.xwpf.usermodel.XWPFParagraph;
import org.apache.poi.xwpf.usermodel.XWPFRun;

import java.io.ByteArrayOutputStream;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.List;
import java.util.Map;

import static org.springframework.util.StringUtils.isEmpty;

public class XWPFDocumentUtils {
    public static byte[] replaceDocument(String path,Map<String,String> fields) throws IOException {
        try (XWPFDocument doc = new XWPFDocument(new FileInputStream(path))) {
            for (XWPFParagraph paragraph : doc.getParagraphs()) {
                String paragraphText = paragraph.getText();
                if (!paragraphText.contains("${")) {
                    continue;
                }

                for (Map.Entry<String,String> field : fields.entrySet()) {
                    String find = "${" + field.getKey() + "}";
                    if (!paragraphText.contains(find)) {
                        continue;
                    }

                    List<XWPFRun> runs = paragraph.getRuns();
                    for (int i = 0; i < runs.size(); i++) {
                        XWPFRun run = runs.get(i);
                        String text = run.text();

                        if (isEmpty(text)) {
                            continue;
                        }

                        if (text.contains("${") || (text.contains("$") && runs.get(i + 1).text().startsWith("{"))) {
                            while (!text.contains("}")) {
                                text += runs.get(i + 1).text();
                                paragraph.removeRun(i + 1);
                            }
                            run.setText(text.contains(find) ? text.replace(find,field.getValue()) : text,0);
                        }
                    }
                }
            }

            try (ByteArrayOutputStream out = new ByteArrayOutputStream()) {
                doc.write(out);
                return out.toByteArray();
            }
        }
    }
}

Spring Boot Rest API

调用replaceDocument()方法生成word文档，如要在Rest API中定义文件名称，使用ResponseEntity并增加header，否则可以直接返回byte[]。

@GetMapping("/api/doc/{heroName}")
public ResponseEntity<byte[]> getDocument(@PathVariable String heroName) {
    try {
        Map<String,String> fields = new HashMap<>();
        fields.put("hero_name",heroName);
        fields.put("create_date","2019年6月");
        byte[] bytes = XWPFDocumentUtil.replaceDocument("template/hero.docx",fields);
        HttpHeaders headers = new HttpHeaders();
        headers.add("Content-Disposition","attachment;filename=hero.docx");
        return ResponseEntity.ok().headers(headers).body(bytes);
    } catch (Exception e) {
        throw new XWPFDocumentException(e.getMessage());
    }
}

配置CORS的ExposedHeaders，否则前台不能读取"Content-Disposition"：

@Bean
CorsConfigurationSource corsConfigurationSource() {
    CorsConfiguration configuration = new CorsConfiguration();
    SecurityProperties.Cors cors = config.getCors();
    configuration.setAllowedMethods(Arrays.asList("*"));
    configuration.setAllowedHeaders(Arrays.asList("Accept","Accept-Encoding","Accept-Language","Authorization","Connection","Content-Type","Host","Origin","Referer","User-Agent","X-Requested-With"));
    configuration.setExposedHeaders(Arrays.asList("Content-Disposition"));
    UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
    source.registerCorsConfiguration("/**",configuration);
    return source;
}

Angular下载文档

可以使用链接直接访问REST URL下载文档，若项目启用了JWT Token验证，则必须使用HttpClient的get方法。
本文使用了FileSaver.js保存文档，开始之前先安装：

npm install --save file-saver

然后在tsconfig.json中添加：

"paths": {
  "file-saver": [
    "node_modules/file-saver/dist/FileSaver.js"
  ]
}

下载方法：

import * as fs from ‘file-saver‘;

downloadDocument() {
  this.httpClient.get(‘yourUrl‘,{observe: ‘response‘,responseType: ‘blob‘}).subscribe(response => {
    fs.saveAs(response.body,this.getFilename(response.headers));
  });
}

private getFilename(headers: HttpHeaders): string {
  const disposition = headers.get(‘Content-Disposition‘);
  if (!disposition || disposition.indexOf(‘filename=‘) < 0) {
    return ‘‘;
  }

  return disposition.substr(disposition.indexOf(‘filename=‘) + 9);
}

或

downloadDocument() {
  this.httpClient.get(‘yourUrl‘,{responseType: ‘blob‘}).subscribe(data => {
    fs.saveAs(data,‘yourFilename‘);
  });
}

参考文档

Excel File – Download from SpringBoot RestAPI + Apache POI + MySQL
Apache POI Word Tutorial