Question

我编写了一段Java代码，该代码在html表中显示了结果。相同的代码多次调用不同的值，我需要显示html表中的所有值。当前使用我的代码它是覆盖并仅显示html中的最后一个方法调用值。

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;

public class TableTest {
    void meth1(String c1,String c2,String c3){
     //business logic
     tableCreation(String c1,String c2,String c3);
     }

    void meth2(String c1,String c2,String c3){
     //business logic
     tableCreation(String c1,String c2,String c3);
     }

    void meth3(String c1,String c2,String c3){
     //business logic
     tableCreation(String c1,String c2,String c3);
     }

    void tableCreation(String c1, String c2, String c3) throws IOException {
        BufferedWriter writer = null;
        try {
            writer = new BufferedWriter(new FileWriter("results.html"));
            writer.write("<html>" + "<body>" + "<table border ='1'>" + "<tr>" + "<th>Col1</th>" + "<th>Col2</th>"
                    + "<th>Col3</th>" + "</tr><tr>");

            /*
             * for (int i=1;i<=3;i++) { writer.write("<td>"); //some business logic here
             * writer.write("-aaaaa-"); writer.write("</td> "); }
             */
            writer.write("<td>");
            writer.write(c1);
            writer.write("</td> ");
            writer.write("<td>");
            writer.write(c2);
            writer.write("</td> ");
            writer.write("<td>");
            writer.write(c3);
            writer.write("</td> ");
            writer.write("</tr></table>" + "</body>" + "</html>");
            writer.close();
        } catch (IOException e) {
            System.out.println("IO EXCEPTION-----" + e);
        }

        System.out.println("----------END---------------");
    }

    public static void main(String[] args) throws IOException {
        // the below method calls are dynamic, don't know how many times
        // tableCreation(..) is being called
        new TableTest().meth1("R1Tst1", "R1Tst2", "R1Tst3");
        new TableTest().meth2("R2Tst1", "R2Tst2", "R2Tst3");
        new TableTest().meth3("R3Tst1", "R3Tst2", "R3Tst3");
    }
}

结果：

 Col1   Col2   Col3
 R3Tst1 R3Tst2 R3Tst3

预期结果：

Col1   Col2   Col3
R1Tst1 R1Tst2 R1Tst3 
R2Tst1 R2Tst2 R2Tst3 
R3Tst1 R3Tst2 R3Tst3

Answer 1

您可以借鉴构建器模式。

下面我要做的是创建HtmlTableBuilder类的实例，在其中添加了html文件的第一部分。之后，您可以使用add()方法添加行，并使用build()方法完成操作，该方法还将添加html文件的结尾部分并返回HtmlTable的实例。这样，您可以写到您的BufferedWriter。

public class HtmlTable {

    String html;

    public HtmlTable(String html) {
        this.html = html;
    }

    public static class HtmlTableBuilder {
        String html;

        public HtmlTableBuilder() {
            html = "<html>" +
                   "<body>" +
                   "<table border ='1'>" +
                   "<tr>" +
                   "<th>Col1</th>" +
                   "<th>Col2</th>" +
                   "<th>Col3</th>" +
                   "</tr>";
        }

        public HtmlTableBuilder addRow(String col1, String col2, String col3) {
            html += "<tr>" +
                    "<td>" +
                    col1 +
                    "</td><td>" +
                    col2 +
                    "</td><td>" +
                    col3 +
                    "</td>" +
                    "</tr>";
            return this;
        }

        public HtmlTable build() {
            html += "</table>" +
                    "</body>" +
                    "</html>";
            HtmlTable toReturn = new HtmlTable(html);
            return toReturn;
        }
    }

    public static void main(String[] args) {
        HtmlTable table = new HtmlTableBuilder()
                .addRow("R1Tst1", "R1Tst2", "R1Tst3")
                .addRow("R2Tst1", "R2Tst2", "R2Tst3")
                .addRow("R3Tst1", "R3Tst2", "R3Tst3")
                .build();
        BufferedWriter writer = new BufferedWriter(new FileWriter("results.html"));
        writer.write(table);
        writer.close();
    }

}

这是一个包含三列的表。当然，您可以利用自己的想象力，将其转换为具有非预定义列数的更通用的解决方案。在这种情况下，您将例如使用Strings方法中的add()列表。

在不使用多个方法调用覆盖表的情况下显示值

1 个答案: