文件内容检索

深藏阁楼爱情的钟 2023-09-25 20:51 140阅读 0赞

定义全局变量

private List returnList = new ArrayList();
    
    private Map linkMap = new HashMap();  //存放关键行数
    
    private Map countMap = new HashMap();  //存放每行要跳过的字符数
    
    private int size;
    
    private Long before;
    
    private Long after;
    
    private String path;//文件路径

检索文件主体方法

public Map logSearch(Long before6,Long after6,String findStr,String logName, String path6, String coding) {
    
        if(before6 == null){
            before6 = 0L;
        }
        if(after6 == null){
            after6 = 0L;
        }
    
        checkParam(before6,after6,findStr,logName,path6);
    
        path6 = path6 + "\\" + logName;
    
        size = 0;
        returnList.clear();//全局变量清空
        linkMap.clear();
        countMap.clear();
        before = before6;
        after = after6;
        path = path6;
    
        String result = "";
    
        String code = "GB2312";
    
        if(!StringUtils.isEmpty(coding)){
            code = coding;
        }
    
        StringBuilder strLink = new StringBuilder();
    
        BufferedReader readerLink = null;
        try {
            readerLink = new BufferedReader(new InputStreamReader(new FileInputStream(path), code));
        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
            throw new BusinessException("文件转码异常");
        } catch (FileNotFoundException e) {
            e.printStackTrace();
            throw new BusinessException("未找到指定文件");
    
        }
    
        int len = 0; //读取字符
        Long i = 0L; //定位要查询字符前一位起始位置
        Long k = 1L; //定位行数(总行数与查询字符出现的行数)
        Long count = 0L;
        int h = 1; //存储集合的索引key
    
    
        countMap.put(1L,0L); //初始化
    
        while (true) {
            try {
                if (!((len = readerLink.read()) != -1)){ break;};
            } catch (IOException e) {
                e.printStackTrace();
                throw new BusinessException("IO异常");
            }
            char lenChar = (char) len;
            strLink.append(lenChar);
            if (lenChar == 10) { //换行符
                if (strLink.toString().contains(findStr)) {
    
                    linkMap.put(h,k);//h为key索引,解析为第x个,k为关键行数
                    h++;
    
                }
                int charSize = strLink.length();
                count+=charSize;
                countMap.put(k+1,count);//第k+1行,需要跳过xx字符
                strLink = new StringBuilder();
                k++;
            }
    
            i++;
        }
    
        size = linkMap.size();
    
        int tol = size;
    
        if(tol > 500){
    
            tol = 500;
        }
    
        for (int n = 1; n < tol+1; n++) {
            // 以跳过的字符数控制开头,以行数k控制结尾
            Long hang  = (Long) linkMap.get(n);
    
            if(hang == null){
                throw new BusinessException("未查询到结果");
            }
    
            Long total = 1L;
            Long chu = 0L;
            Long charSize = 0L;
    
            if(hang == 1L){ //指针与顶重合
    
                charSize = 0L;
                total = 1 + after;
    
            }else if(before >= hang || hang == before+1) {  //触顶或破顶,使用新的逻辑
    
                before = hang - 1;
                chu = hang - before;
                charSize = (Long) countMap.get(chu);
                total = before + 1 + after;
    
            }else {//无触顶,普通逻辑(包含before为0,after为0的特殊情况)
    
                chu = hang-before;
                charSize  = (Long) countMap.get(chu);
                total = before + 1 + after;
            }
    
            StringBuilder str = new StringBuilder();
            BufferedReader reader = null;
            try {
                reader = new BufferedReader(new InputStreamReader(new FileInputStream(path), code));
            } catch (UnsupportedEncodingException e) {
                e.printStackTrace();
                throw new BusinessException("文件转码异常");
            } catch (FileNotFoundException e) {
                e.printStackTrace();
                throw new BusinessException("未找到指定文件");
            }
            len = 0;
            if(charSize != 0){
                try {
                    reader.skip(charSize);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            Long j = 1L;//内置计数器
            while (true) {
                try {
                    if (!((len = reader.read()) != -1)){ break;};
                } catch (IOException e) {
                    e.printStackTrace();
                    throw new BusinessException("IO异常");
                }
                boolean flag = false;//外置控制器->内循环控制外循环
                char lenChar = (char) len;
                str.append(lenChar);
                if (lenChar == 10) {//换行符
    
                    if(j.equals(total)){
                        flag =true;
                    }
                    j++;
                }
    
                if(flag){
                    break;
                }
    
            }
    
            if(n == 1){//默认返回查询到的第一个结果
    
                result = str.toString();
            }
    
            returnList.add(str.toString());
        }
    
        if(returnList.size() == 0){
    
            throw new BusinessException("未查询到与该字段有关数据");
        }
    
        Map returnMap = new HashMap();
        returnMap.put("str",result);
        returnMap.put("total",size);
        returnMap.put("index",0);
    
    
        return returnMap;
    
    }

private void checkParam(Long before,Long after,String findStr,String logName, String path){
        //参数校验
        if(before > 10){
            throw new BusinessException("检索时前面行数不能超过10");
        }
        if(after > 100){
            throw new BusinessException("检索时后面行数不能超过100");
        }
        if(StringUtils.isEmpty(findStr)){
            throw new BusinessException("查找的字段为空");
        }
    
        if(StringUtils.isEmpty(path) || StringUtils.isEmpty(logName)){
            throw new BusinessException("缺少参数");
        }
    }

通过前端传来的参数(页数与前一页后一页来浏览数据)

public Map prevOrNext(Integer index, String coding) {
    
        int size = returnList.size();
    
        if(StringUtils.isEmpty(index)){
    
            throw new BusinessException("暂无数据");
        }
    
        if(size == 0){
    
            throw new BusinessException("请先进行查询");
        }
        if(index < 0){
    
            throw new BusinessException("暂无数据");
        }
    
        if(index > this.size){
    
            throw new BusinessException("这是最后一条数据了");
        }
    
        if(index < 500){
    
            String result = (String) returnList.get(index-1);
    
            if(StringUtils.isEmpty(result)){
    
                throw new BusinessException("暂无数据");
            }
    
            Map returnMap = new HashMap();
            returnMap.put("str",result);
            returnMap.put("index",index);
            returnMap.put("flag",true);
    
            return returnMap;
        }else {
    
                // 以跳过的字符数控制开头,以行数k控制结尾
                Long hang  = (Long) linkMap.get(index-1);
    
                if(hang == null){
                    throw new BusinessException("未查询到结果");
                }
    
                Long total = 1L;
                Long chu = 0L;
                Long charSize = 0L;
    
                if(hang == 1L){ //指针与顶重合
    
                    charSize = 0L;
                    total = 1 + after;
    
                }else if(before >= hang || hang == before+1) {  //触顶或破顶,使用新的逻辑
    
                    before = hang - 1;
                    chu = hang - before;
                    charSize = (Long) countMap.get(chu);
                    total = before + 1 + after;
    
                }else {//无触顶,普通逻辑(包含before为0,after为0的特殊情况)
    
                    chu = hang-before;
                    charSize  = (Long) countMap.get(chu);
                    total = before + 1 + after;
                }
    
                StringBuilder str = new StringBuilder();
                BufferedReader reader = null;
                try {
                    reader = new BufferedReader(new InputStreamReader(new FileInputStream(path), coding));
                } catch (UnsupportedEncodingException e) {
                    e.printStackTrace();
                    throw new BusinessException("文件转码异常");
                } catch (FileNotFoundException e) {
                    e.printStackTrace();
                    throw new BusinessException("未找到指定文件");
                }
                int len = 0;
                if(charSize != 0){
                    try {
                        reader.skip(charSize);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
                Long j = 1L;//内置计数器
                while (true) {
                    try {
                        if (!((len = reader.read()) != -1)){ break;};
                    } catch (IOException e) {
                        e.printStackTrace();
                        throw new BusinessException("IO异常");
                    }
                    boolean flag = false;//外置控制器->内循环控制外循环
                    char lenChar = (char) len;
                    str.append(lenChar);
                    if (lenChar == 10) {//换行符
    
                        if(j.equals(total)){
                            flag =true;
                        }
                        j++;
                    }
    
                    if(flag){
                        break;
                    }
    
                }
    
                String result = str.toString();
    
                Map returnMap = new HashMap();
                returnMap.put("str",result);
                returnMap.put("index",index);
                returnMap.put("flag",true);
                return returnMap;
            }
    
    }