Java 如何从文本文件中读取和存储数据，其中第一行是标题，其他行是相关数据
我有一个300行左右的文本文件。格式如下：Java 如何从文本文件中读取和存储数据，其中第一行是标题，其他行是相关数据,java,algorithm,file-io,Java,Algorithm,File Io,我有一个300行左右的文本文件。格式如下： Name Amount Unit CountOfOrder A 1 ml 5000 B 1 mgm 4500 C 4 gm 4200 // more data public static void main(Str
Name Amount Unit CountOfOrder
A 1 ml 5000
B 1 mgm 4500
C 4 gm 4200
// more data
public static void main(String args[]) throws FileNotFoundException, IOException {
List<String> headerList = new ArrayList<String>();
List<String> column1 = new ArrayList<String>();
List<String> column2 = new ArrayList<String>();
List<String> column3 = new ArrayList<String>();
List<String> column4 = new ArrayList<String>();
int lineCount=0;
BufferedReader br = new BufferedReader(new FileReader("file.txt"));
try {
StringBuilder sb = new StringBuilder();
String line = br.readLine();
String tokens[];
while (line != null) {
tokens = line.split("\t");
if(lineCount != 0)
{
int count = 0;
column1.add(tokens[count]); ++count;
column2.add(tokens[count]); ++count;
column3.add(tokens[count]); ++count;
column4.add(tokens[count]); ++count;
continue;
}
if(lineCount==0){
for(int count=0; count<tokens.length; count++){
headerList.add(tokens[count]);
lineCount++;
}
}
}
} catch (IOException e) {
} finally {
br.close();
}
}
public static void main(String args[]) throws FileNotFoundException, IOException {
List<String> headerList = new ArrayList<String>();
List<String> column1 = new ArrayList<String>();
List<String> column2 = new ArrayList<String>();
List<String> column3 = new ArrayList<String>();
List<String> column4 = new ArrayList<String>();
int lineCount=0;
BufferedReader br = new BufferedReader(new FileReader("file.txt"));
try {
StringBuilder sb = new StringBuilder();
String line = br.readLine();
String tokens[];
while (line != null) {
tokens = line.split("\t");
if(lineCount != 0)
{
int count = 0;
column1.add(tokens[count]); ++count;
column2.add(tokens[count]); ++count;
column3.add(tokens[count]); ++count;
column4.add(tokens[count]); ++count;
continue;
}
if(lineCount==0){
for(int count=0; count<tokens.length; count++){
headerList.add(tokens[count]);
lineCount++;
}
}
}
} catch (IOException e) {
} finally {
br.close();
}
}
for each line in file:
array[0] = {data from the 'Name' column}
array[1] = {data from the 'Amount' column}
array[2] = {data from the 'Unit' column}
array[3] = {data from the 'CountOfOrder' column}
....
someOtherMethods(array);
....
public static void main(String args[]) throws FileNotFoundException, IOException {
List<String> headerList = new ArrayList<String>();
List<String> column1 = new ArrayList<String>();
List<String> column2 = new ArrayList<String>();
List<String> column3 = new ArrayList<String>();
List<String> column4 = new ArrayList<String>();
int lineCount=0;
BufferedReader br = new BufferedReader(new FileReader("file.txt"));
try {
StringBuilder sb = new StringBuilder();
String line = br.readLine();
String tokens[];
while (line != null) {
tokens = line.split("\t");
if(lineCount != 0)
{
int count = 0;
column1.add(tokens[count]); ++count;
column2.add(tokens[count]); ++count;
column3.add(tokens[count]); ++count;
column4.add(tokens[count]); ++count;
continue;
}
if(lineCount==0){
for(int count=0; count<tokens.length; count++){
headerList.add(tokens[count]);
lineCount++;
}
}
}
} catch (IOException e) {
} finally {
br.close();
}
}
public static void main(String args[]) throws FileNotFoundException, IOException {
List<String> headerList = new ArrayList<String>();
List<String> column1 = new ArrayList<String>();
List<String> column2 = new ArrayList<String>();
List<String> column3 = new ArrayList<String>();
List<String> column4 = new ArrayList<String>();
int lineCount=0;
BufferedReader br = new BufferedReader(new FileReader("file.txt"));
try {
StringBuilder sb = new StringBuilder();
String line = br.readLine();
String tokens[];
while (line != null) {
tokens = line.split("\t");
if(lineCount != 0)
{
int count = 0;
column1.add(tokens[count]); ++count;
column2.add(tokens[count]); ++count;
column3.add(tokens[count]); ++count;
column4.add(tokens[count]); ++count;
continue;
}
if(lineCount==0){
for(int count=0; count<tokens.length; count++){
headerList.add(tokens[count]);
lineCount++;
}
}
}
} catch (IOException e) {
} finally {
br.close();
}
}
public static void main(String args[]) throws FileNotFoundException, IOException {
List<String> headerList = new ArrayList<String>();
List<String> column1 = new ArrayList<String>();
List<String> column2 = new ArrayList<String>();
List<String> column3 = new ArrayList<String>();
List<String> column4 = new ArrayList<String>();
int lineCount=0;
BufferedReader br = new BufferedReader(new FileReader("file.txt"));
try {
StringBuilder sb = new StringBuilder();
String line = br.readLine();
String tokens[];
while (line != null) {
tokens = line.split("\t");
if(lineCount != 0)
{
int count = 0;
column1.add(tokens[count]); ++count;
column2.add(tokens[count]); ++count;
column3.add(tokens[count]); ++count;
column4.add(tokens[count]); ++count;
continue;
}
if(lineCount==0){
for(int count=0; count<tokens.length; count++){
headerList.add(tokens[count]);
lineCount++;
}
}
}
} catch (IOException e) {
} finally {
br.close();
}
}
有人对此有什么想法吗？请帮忙 您可以使用读取文件
public static void main(String args[]) throws FileNotFoundException, IOException {
List<String> headerList = new ArrayList<String>();
List<String> column1 = new ArrayList<String>();
List<String> column2 = new ArrayList<String>();
List<String> column3 = new ArrayList<String>();
List<String> column4 = new ArrayList<String>();
int lineCount=0;
BufferedReader br = new BufferedReader(new FileReader("file.txt"));
try {
StringBuilder sb = new StringBuilder();
String line = br.readLine();
String tokens[];
while (line != null) {
tokens = line.split("\t");
if(lineCount != 0)
{
int count = 0;
column1.add(tokens[count]); ++count;
column2.add(tokens[count]); ++count;
column3.add(tokens[count]); ++count;
column4.add(tokens[count]); ++count;
continue;
}
if(lineCount==0){
for(int count=0; count<tokens.length; count++){
headerList.add(tokens[count]);
lineCount++;
}
}
}
} catch (IOException e) {
} finally {
br.close();
}
}
CSVReader reader=new CSVReader（new FileReader（“yourfile.txt”），“\t”）；
列表行=reader.readAll（）；
第一行包含标题。您可以读取文件的每一行，并假设文件的第一行具有列标题，您可以解析该行以获得所有列的名称
String[] column_headers = firstline.split("\t");
public static void main(String args[]) throws FileNotFoundException, IOException {
List<String> headerList = new ArrayList<String>();
List<String> column1 = new ArrayList<String>();
List<String> column2 = new ArrayList<String>();
List<String> column3 = new ArrayList<String>();
List<String> column4 = new ArrayList<String>();
int lineCount=0;
BufferedReader br = new BufferedReader(new FileReader("file.txt"));
try {
StringBuilder sb = new StringBuilder();
String line = br.readLine();
String tokens[];
while (line != null) {
tokens = line.split("\t");
if(lineCount != 0)
{
int count = 0;
column1.add(tokens[count]); ++count;
column2.add(tokens[count]); ++count;
column3.add(tokens[count]); ++count;
column4.add(tokens[count]); ++count;
continue;
}
if(lineCount==0){
for(int count=0; count<tokens.length; count++){
headerList.add(tokens[count]);
lineCount++;
}
}
}
} catch (IOException e) {
} finally {
br.close();
}
}
这将为您提供所有列的名称，您现在只需在选项卡上通过拆分读取，它们将全部对齐。您可以执行以下操作：
BufferedReader in = new BufferedReader(new InputStreamReader(
new FileInputStream(FILE)));
String line = null;
String[] headers = null;
String[] data = null;
Map<String, List<String>> contents = new HashMap<String, List<String>>();
if ((line = in.readLine()) != null) {
headers = line.split("\t");
}
for(String h : headers){
contents.put(h, new ArrayList<String>());
}
while ((line = in.readLine()) != null) {
data = line.split("\t");
if(data.length != headers.length){
throw new Exception();
}
for(int i = 0; i < data.length; i++){
contents.get(headers[i]).add(data[i]);
}
}
public static void main(String args[]) throws FileNotFoundException, IOException {
List<String> headerList = new ArrayList<String>();
List<String> column1 = new ArrayList<String>();
List<String> column2 = new ArrayList<String>();
List<String> column3 = new ArrayList<String>();
List<String> column4 = new ArrayList<String>();
int lineCount=0;
BufferedReader br = new BufferedReader(new FileReader("file.txt"));
try {
StringBuilder sb = new StringBuilder();
String line = br.readLine();
String tokens[];
while (line != null) {
tokens = line.split("\t");
if(lineCount != 0)
{
int count = 0;
column1.add(tokens[count]); ++count;
column2.add(tokens[count]); ++count;
column3.add(tokens[count]); ++count;
column4.add(tokens[count]); ++count;
continue;
}
if(lineCount==0){
for(int count=0; count<tokens.length; count++){
headerList.add(tokens[count]);
lineCount++;
}
}
}
} catch (IOException e) {
} finally {
br.close();
}
}
BufferedReader in=新的BufferedReader（新的InputStreamReader(
新文件输入流（文件））；
字符串行=null；
String[]headers=null；
字符串[]数据=null；
映射内容=新的HashMap（）；
如果（（line=in.readLine（））！=null）{
页眉=行分割（“\t”）；
}
for（字符串h:标题）{
put（h，newarraylist（））；
}
而（（line=in.readLine（））！=null）{
数据=行分割（“\t”）；
if（data.length！=headers.length）{
抛出新异常（）；
}
对于（int i=0；i它会给你灵活性，只需要做一次地图。然后，您可以从地图中获取数据列表，因此它应该是一个方便的数据结构，供程序的其余部分使用。这将为您提供列的单个列表
public static void main(String args[]) throws FileNotFoundException, IOException {
List<String> headerList = new ArrayList<String>();
List<String> column1 = new ArrayList<String>();
List<String> column2 = new ArrayList<String>();
List<String> column3 = new ArrayList<String>();
List<String> column4 = new ArrayList<String>();
int lineCount=0;
BufferedReader br = new BufferedReader(new FileReader("file.txt"));
try {
StringBuilder sb = new StringBuilder();
String line = br.readLine();
String tokens[];
while (line != null) {
tokens = line.split("\t");
if(lineCount != 0)
{
int count = 0;
column1.add(tokens[count]); ++count;
column2.add(tokens[count]); ++count;
column3.add(tokens[count]); ++count;
column4.add(tokens[count]); ++count;
continue;
}
if(lineCount==0){
for(int count=0; count<tokens.length; count++){
headerList.add(tokens[count]);
lineCount++;
}
}
}
} catch (IOException e) {
} finally {
br.close();
}
}
publicstaticvoidmain（字符串args[]）抛出FileNotFoundException、IOException{
列表标题列表=新的ArrayList（）；
List column1=新的ArrayList（）；
List column2=新的ArrayList（）；
List column3=新的ArrayList（）；
List column4=新的ArrayList（）；
int lineCount=0；
BufferedReader br=新的BufferedReader（新文件读取器（“file.txt”）；
试一试{
StringBuilder sb=新的StringBuilder（）；
String line=br.readLine（）；
字符串标记[]；
while（行！=null）{
令牌=行分割（“\t”）；
如果（行数！=0）
{
整数计数=0；
列1.添加（令牌[count]）；++count；
第2列。添加（令牌[count]）；++count；
第3列。添加（令牌[count]）；++count；
第4列。添加（令牌[count]）；++count；
继续；
}
如果（行数==0）{
对于（int count=0；count使用标准java.util.Scanner
public static void main(String args[]) throws FileNotFoundException, IOException {
List<String> headerList = new ArrayList<String>();
List<String> column1 = new ArrayList<String>();
List<String> column2 = new ArrayList<String>();
List<String> column3 = new ArrayList<String>();
List<String> column4 = new ArrayList<String>();
int lineCount=0;
BufferedReader br = new BufferedReader(new FileReader("file.txt"));
try {
StringBuilder sb = new StringBuilder();
String line = br.readLine();
String tokens[];
while (line != null) {
tokens = line.split("\t");
if(lineCount != 0)
{
int count = 0;
column1.add(tokens[count]); ++count;
column2.add(tokens[count]); ++count;
column3.add(tokens[count]); ++count;
column4.add(tokens[count]); ++count;
continue;
}
if(lineCount==0){
for(int count=0; count<tokens.length; count++){
headerList.add(tokens[count]);
lineCount++;
}
}
}
} catch (IOException e) {
} finally {
br.close();
}
}
String aa = " asd 9 1 3 \n d -1 4 2";
Scanner ss = new Scanner(aa);
ss.useDelimiter("\n");
while ( ss.hasNext()){
String line = ss.next();
Scanner fs = new Scanner(line);
System.out.println( "1>"+ fs.next()+" " +fs.nextInt() +" " +fs.nextLong()+" " +fs.nextBigDecimal());
}
使用一堆hashmap是可以的……我不会害怕；）
如果您需要处理大量数据……那么尝试将您的问题转化为数据处理转换
public static void main(String args[]) throws FileNotFoundException, IOException {
List<String> headerList = new ArrayList<String>();
List<String> column1 = new ArrayList<String>();
List<String> column2 = new ArrayList<String>();
List<String> column3 = new ArrayList<String>();
List<String> column4 = new ArrayList<String>();
int lineCount=0;
BufferedReader br = new BufferedReader(new FileReader("file.txt"));
try {
StringBuilder sb = new StringBuilder();
String line = br.readLine();
String tokens[];
while (line != null) {
tokens = line.split("\t");
if(lineCount != 0)
{
int count = 0;
column1.add(tokens[count]); ++count;
column2.add(tokens[count]); ++count;
column3.add(tokens[count]); ++count;
column4.add(tokens[count]); ++count;
continue;
}
if(lineCount==0){
for(int count=0; count<tokens.length; count++){
headerList.add(tokens[count]);
lineCount++;
}
}
}
} catch (IOException e) {
} finally {
br.close();
}
}
例如：
将所有数据读入hashmap，但使用一些JPA
实现将它们存储在数据库中……然后您可以对数据进行“a”循环；）\您只需要一个散列映射就可以将列名映射到正确的列索引。您可以像以前一样，通过使用整数索引来填充数组，以便按您需要的名称检索列使用array[hashmap.get（“Amount”）]
是否有某种分隔符用于分隔每列数据？如果格式更改，可以使用列表存储列的名称并使用索引获取字段。否则，将数据封装在类中。@JoshM，很抱歉我忘了提到这一点。是的，分隔符是制表符（\t）@D.Q.文件中是否包含列标题？@collapsar，您好，这个解决方案太棒了！我想在地图中存储数据，所以我从来没有想过在地图中使用数字作为值！请您将您的评论作为答案，以便我可以接受它？非常感谢！在您的hashMap中，您的键不应该是String[]，因为header是一个String[]数组，而不是String。此解决方案是动态的，因此在添加另一列时不会失败。在我看来，如果将数组存储为键，则使用Map的整个目的似乎都会失败。我正在寻找CSV答案，但很失望地发现仍然是“逐行手动读取”-答案。谢谢你让我振作起来：）
public static void main(String args[]) throws FileNotFoundException, IOException {
List<String> headerList = new ArrayList<String>();
List<String> column1 = new ArrayList<String>();
List<String> column2 = new ArrayList<String>();
List<String> column3 = new ArrayList<String>();
List<String> column4 = new ArrayList<String>();
int lineCount=0;
BufferedReader br = new BufferedReader(new FileReader("file.txt"));
try {
StringBuilder sb = new StringBuilder();
String line = br.readLine();
String tokens[];
while (line != null) {
tokens = line.split("\t");
if(lineCount != 0)
{
int count = 0;
column1.add(tokens[count]); ++count;
column2.add(tokens[count]); ++count;
column3.add(tokens[count]); ++count;
column4.add(tokens[count]); ++count;
continue;
}
if(lineCount==0){
for(int count=0; count<tokens.length; count++){
headerList.add(tokens[count]);
lineCount++;
}
}
}
} catch (IOException e) {
} finally {
br.close();
}
}