轉換過程出現這個異常
Caused by: java.lang.NullPointerException
at org.apache.poi.xwpf.converter.core.styles.run.RunUnderlineValueProvider.getValue(RunUnderlineValueProvider.java:40)

檢視原始碼得知是程式碼寫的不嚴謹

return (rPr != null && rPr.isSetU()) ? UnderlinePatterns.valueOf(rPr.getU().getVal().intValue
 
()) : null;

rPr.getU().getVal().intValue()這裡容易出現空指標問題

解決辦法:

• 在自己的專案中新建一個package名為org.apache.poi.xwpf.converter.core.styles.run
• 新建一個RunUnderlineValueProvider類,程式碼如下:

package org.apache.poi.xwpf.converter.core.styles.run;

import org.apache.poi.xwpf.converter.core.styles.XWPFStylesDocument;
import
 
 org.apache.poi.xwpf.usermodel.UnderlinePatterns;
import org.openxmlformats.schemas.wordprocessingml.x2006.main.CTRPr;
import org.openxmlformats.schemas.wordprocessingml.x2006.main.CTUnderline;
import org.openxmlformats.schemas.wordprocessingml.x2006.main.STUnderline.Enum;

/**
 * 解決空指標異常,jar裡面的寫法不嚴謹
 */
public class
 
 RunUnderlineValueProvider extends AbstractRunValueProvider<UnderlinePatterns> {

    public static final RunUnderlineValueProvider INSTANCE = new RunUnderlineValueProvider();

    @Override
    public UnderlinePatterns getValue(CTRPr rPr, XWPFStylesDocument stylesDocument) {
        if(rPr == null) {
            return null;
        }
        if(rPr.isSetU()) {
            CTUnderline u = rPr.getU();
            if(u != null) {
                Enum val = u.getVal();
                if(val != null) {
                    return UnderlinePatterns.valueOf(val.intValue());
                }
            }
        }
        return null;

        // old code
//      return (rPr != null && rPr.isSetU())
//              ? UnderlinePatterns.valueOf(rPr.getU().getVal().intValue()) : null;
    }
}

這樣系統會優先呼叫.