JAVAで掲示板を作成しているが、ファイルに書き込めるが、nullと表示されているので、原因を教えてください。
BoardSevlet.java
import java.io.IOException;
import java.io.PrintWriter;
import java.io.FileWriter;
import java.io.BufferedWriter;
import java.util.ArrayList;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
@WebServlet("/BordServlet")
public class BordServlet extends HttpServlet {
@Override protected void doPost( HttpServletRequest request, HttpServletResponse response ) throws ServletException, IOException { this.doGet( request, response ); } @SuppressWarnings("unused") @Override protected void doGet( HttpServletRequest request, HttpServletResponse response ) throws ServletException, IOException { response.setContentType( "text/html;charset=UTF-8" ); PrintWriter out = response.getWriter(); out.println( "<html>" ); out.println( "<head>" ); out.println( "<title>BordServlet</title>" ); out.println( "</head>" ); out.println( "<body>" ); out.println( "<h1>掲示板</h1>" ); out.println( "<form action='/TomcatTest/BordServlet' method='get'>" ); out.println( "<table>" ); out.println( "<tr><th>発信者ID</th><td><input type = text name = \"id1\"></td></tr>" ); out.println( "<tr><th>タイトル</th><td><input type = text name = \"title1\"></td></tr>" ); out.println( "<tr><th>本文</th><td> < textarea name = \"body1\" rows=5></textarea></td></tr>" ); out.println( "</table>" ); out.println( "<br>" ); out.println( "<input type=submit value=\"投稿\">" ); out.println( "</form>" ); String id1 = null; String title1 = null; String body1 = null; if ( request.getParameter( "id" ) == null && request.getParameter( "title" ) == null && request.getParameter( "body" ) == null ) { id1 = ""; title1 = ""; body1 = ""; } else { id1 = new String( request.getParameter( "id" ) ); title1 = new String( request.getParameter( "title" ) ); body1 = new String( request.getParameter( "body" ) ); } FileWriter fw = new FileWriter(request.getRealPath("WEB-INF\\classes\\bbs_history.txt")); BufferedWriter bw = new BufferedWriter(fw); bw.write(request.getParameter("id1") + "\r\n"); bw.write(request.getParameter("title1") + "\r\n"); bw.write(request.getParameter("body1") + "\r\n"); bw.close(); ArrayList<Article> aList = new ArrayList<>(); ServletContext sc = this.getServletContext(); aList = (ArrayList<Article>) sc.getAttribute( "0" ); if ( aList == null ) { aList = new ArrayList<>(); } if ( id1.equals( "" ) && title1.equals( "" ) && body1.equals( "" ) ) { } else { for ( Article article : aList ) { if ( article.getSenderID().equals( "" ) && article.getTitle().equals( "" ) && article.getBody().equals( "" ) ) { } else { out.println( "<hr>" ); out.println( "発信者ID" ); out.println( "<p>" + article.getSenderID() + "</p>" ); out.println( "タイトル" ); out.println( "<p>" + article.getTitle() + "</p>" ); out.println( "本文" ); out.println( "<pre>" + article.getBody() + "</pre>" ); out.println( "<hr>" ); } } } sc.setAttribute( "0", aList ); out.println( "</body>" ); out.println( "</html>" ); }
}
Article.java
public class Article {
private String id; private String title; private String body; public Article( String id, String title, String body ) { setSenderID( id ); setTitle( title ); setBody( body ); } public String getSenderID() { return id; } public String getTitle() { return title; } public String getBody() { return body; } public void setSenderID( String string ){ id = string; } public void setTitle( String string ) { title = string; } public void setBody( String string ) { body = string; }
}