由于用到gson，需要导入gson库。首先封装model类:
importjava.util.List;
public class FileModel {
private String name;
private String type;
private String path;
private List children;
public FileModel(String name, String type, String path) {
super();
this.name = name;
this.type = type;
this.path = path;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
public String getPath() {
return path;
}
public void setPath(String path) {
this.path = path;
}
public List getChildren() {
return children;
}
public void setChildren(List children) {
this.children = children;
}
}
编写servlet，实现功能
importjava.io.File;
importjava.io.FileInputStream;
importjava.io.FilenameFilter;
importjava.io.IOException;
importjava.io.PrintWriter;
importjava.util.ArrayList;
importjava.util.List;
importjavax.servlet.ServletException;
importjavax.servlet.annotation.WebServlet;
importjavax.servlet.http.HttpServlet;
importjavax.servlet.http.HttpServletRequest;
importjavax.servlet.http.HttpServletResponse;
importcom.google.gson.Gson;
@WebServlet("/getFiles")
public class ListFileController extends HttpServlet {
private static final long serialVersionUID = 1L;
private Gson gson = new Gson();
private String rootFile = "/Users/terry/Books";
public ListFileController() {
super();
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
rootFile = request.getServletContext().getRealPath(".");
response.setHeader("content-type","application/json;charset=UTF-8");
response.setCharacterEncoding("UTF-8");
PrintWriter out = response.getWriter();
File file = new File(rootFile);
List fileModel = getFileList(file);
StringjsonString=gson.toJson(fileModel);
out.println(jsonString);
out.flush();
out.close();
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
doGet(request, response);
}
private final FilenameFilter FILE_ILTER = new FilenameFilter() {
@Override
public boolean accept(File dir, String name) {
File acceptFile = new File(dir, name);
boolean result = acceptFile.isDirectory() || "%PDF".equalsIgnoreCase(getFileHeader(acceptFile));
return result;
}
};
final String getFileHeader(final File file) {
FileInputStream is = null;
String value = null;
try {
is = new FileInputStream(file);
byte[] b = new byte[4];
is.read(b, 0, b.length);
value=newString(b);
} catch (Exception e) {
} finally {
if(null!=is){
try{
is.close();
} catch (IOException e) {
}
}
}
return value;
}
List getFileList(final File startFileDir) {
List result = null;
synchronized (this) {
result = new ArrayList<>();
File[] fileDirs = startFileDir.listFiles(FILE_ILTER);
for (File file : fileDirs) {
FileModel fileModel = new FileModel(file.getName(), file.isFile()?"2":"1",file.getPath().replace(rootFile, ""));
result.add(fileModel);
if (file.isDirectory()) {
List deeperList = getFileList(file);
if(deeperList!=null && !deeperList.isEmpty()) {
fileModel.setChildren(deeperList);
}
}
}
}
return result;
}
}