http断点续传简单实现（java)

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0 发表于: 2006-05-10

/*
**SiteFileFetch.java
*/
package NetFox;
import java.io.*;
import java.net.*;

public class SiteFileFetch extends Thread {

SiteInfoBean siteInfoBean = null; //文件信息Bean
long[] nStartPos; //开始位置
long[] nEndPos; //结束位置
FileSplitterFetch[] fileSplitterFetch; //子线程对象
long nFileLength; //文件长度
boolean bFirst = true; //是否第一次取文件
boolean bStop = false; //停止标志
File tmpFile; //文件下载的临时信息
DataOutputStream output; //输出到文件的输出流

//负责整个文件的抓取，控制内部线程（FileSplitterFetch类）
public SiteFileFetch(SiteInfoBean bean) throws IOException
{
siteInfoBean = bean;
//tmpFile = File.createTempFile ("zhong","1111",new File(bean.getSFilePath()));
tmpFile = new File(bean.getSFilePath()+File.separator + bean.getSFileName()+".info");
if(tmpFile.exists ())
{
bFirst = false;
read_nPos();
}
else
{
nStartPos = new long[bean.getNSplitter()];
nEndPos = new long[bean.getNSplitter()];
}

}

public void run()
{
//获得文件长度
//分割文件
//实例FileSplitterFetch
//启动FileSplitterFetch线程
//等待子线程返回
try{
if(bFirst)
{
nFileLength = getFileSize();
if(nFileLength == -1)
{
System.err.println("File Length is not known!");
}
else if(nFileLength == -2)
{
System.err.println("File is not access!");
}
else
{
for(int i=0;i<nStartPos.length;i++)
{
nStartPos = (long)(i*(nFileLength/nStartPos.length)); ,^CG\);
} sz%]rN6$
for(int i=0;i<nEndPos.length-1;i++) NfQQJ@*
{ !gyW15z'
nEndPos = nStartPos[i+1]; (Qw>P42J
} : HU|BJ>
nEndPos[nEndPos.length-1] = nFileLength; ~rrl"a>
} N\s-{7K
} .`KzA]&#
VSO(DCr"L
7lYf+&JZ
//启动子线程 Bs3&yEq(
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; kb$Yc)+R4
for(int i=0;i<nStartPos.length;i++) 'ym Mu}q
{ nIOSP:'>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >8>s K(S]
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), k0FAI0~(
nStartPos,nEndPos,i); \Dr( /n
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); v\(6uej^
fileSplitterFetch.start(); .5SYN-@
} j7Zv"Vq@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,WsG,Q(K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >t9DI
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?Z!R
nEndPos = " + nFileLength); H9;IA>
// fileSplitterFetch[nPos.length-1].start(); wg k[_i
?;w`hA3ei
kg(}%Ih
//等待子线程结束 U |eh
//int count = 0; y'6lfThT
//是否结束while循环 Bvj
boolean breakWhile = false; Nj?Q{ztS
wKcuIc$
s{c|J#s
while(!bStop) ( ?e Et&
{ )C\/(
write_nPos(); u>] )q7s
Utility.sleep(500); &D|+tu{
breakWhile = true; -jNnx*
18j>x3tn
N3Q .4? z9
for(int i=0;i<nStartPos.length;i++) |A|K);
{ vytO8m%U
if(!fileSplitterFetch.bDownOver) a&kt!%p:
{ mq}uq9<
breakWhile = false; h0x'QiCc
break; 0}` -<(
} CG35\b;Q
} ~4#D G^5
if(breakWhile) ^;{uop"DS
break; O#!|2qN
4"nYxL"<4
lkp$rJ#6
//count++; Om;`"5
//if(count>4) h`vT[u~l
// siteStop(); 1JOoICjB
} y(a>Y! dgU
{QN 5QGvK
8B "^}y\0
System.err.println("文件下载结束！"); WK0IagYw
} :"nh76xg<
catch(Exception e){e.printStackTrace ();} 44k8IYC*o
} wrJ"(:VZ
}0/l48G
Ai:,cY5%
//获得文件长度 ,l,q;]C%
public long getFileSize() Q7zpu/5?
{ B<.ZW}#v
int nFileLength = -1; M4 }))
try{ 1'\s7P
URL url = new URL(siteInfoBean.getSSiteURL()); oOLj? 0t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g^#,!e
httpConnection.setRequestProperty("User-Agent","NetFox"); #N"QTD|i
McbbEs=)
9B>P Qbs
int responseCode=httpConnection.getResponseCode(); UsCaO<A
if(responseCode>=400) hoiC J}us
{ DHvZ:)aT}
processErrorCode(responseCode); ^%\MOjSN
return -2; //-2 represent access is error _Wp.s]D [
} }:s.m8LC5n
s|[qq7
! P$[$W
String sHeader; >C5u>@%9O
Qip@L WvT
bx-:aC)]2
for(int i=1;;i++) Osy_C<O
{ (b1e!gJpy
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); |WT]s B0Eq
//Utility.log(in.readLine()); G~4G$YL*
sHeader=httpConnection.getHeaderFieldKey(i); 8RVRfy,w
if(sHeader!=null) pUu<0a^
{ zW`a]n.
if(sHeader.equals("Content-Length")) T}"[f/:N/
{ UQP>yuSx
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *vqUOh
break; +KTHZpp!c2
} <1QXZfQ"
} 0q]0+o*%
else =L?2[a$2;
break; /*"pylm
} nYBa+>3BDf
} ~g@}A
catch(IOException e){e.printStackTrace ();} hdmKD0
catch(Exception e){e.printStackTrace ();} _ib @<%
CZ{7?:^f
?jvuTS2
Utility.log(nFileLength); 4#t-?5"
sfy}J1xIL
nuA 0%K
return nFileLength; 8WKY 4nkj
} &xt GabNk
(Y^tky$9
e:rbyzf#
//保存下载信息（文件指针位置） 5-&"nn2*}1
private void write_nPos() j^hLn>
{ v}IhO~`uEq
try{ LEX @hkh
output = new DataOutputStream(new FileOutputStream(tmpFile)); bu08`P9
output.writeInt(nStartPos.length); z"Cyjmg"
for(int i=0;i<nStartPos.length;i++) Zdfh*MHMg
{ "-rqL
// output.writeLong(nPos); 5;HCNwX
output.writeLong(fileSplitterFetch.nStartPos); k7cY^&o
output.writeLong(fileSplitterFetch.nEndPos); DhsvN&yNM
} RU>qj *e
output.close(); U9 mK^
} J`{o`>
catch(IOException e){e.printStackTrace ();} jmP;(j.|
catch(Exception e){e.printStackTrace ();} hp2$[p6O
} *{\))Zmhd
MhB>bnWXR
3od16{YH
//读取保存的下载信息（文件指针位置） *O_^C
private void read_nPos() 2n-kJl`: O
{ &H+n0v
try{ 6)20%*[
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t-<BRnxhE
int nCount = input.readInt(); roBb8M|q
nStartPos = new long[nCount]; Tb8r+~HK
nEndPos = new long[nCount]; 8yH)9#>
for(int i=0;i<nStartPos.length;i++) !DF5NAE
{ x]3[0K5;
nStartPos = input.readLong(); lXzm)
nEndPos = input.readLong(); V\l@_%D[(v
} d9%P[(yM^
input.close(); Hk(=_[S
} AD@ {7
catch(IOException e){e.printStackTrace ();} ,*?[Rg0]+
catch(Exception e){e.printStackTrace ();} v53|)]V
} TNK1E
TZ!@IBu
)8SWU)/
private void processErrorCode(int nErrorCode) ^6LnB#C&
{ Ki&a"Fu3
System.err.println("Error Code : " + nErrorCode); @~UQU)-(
} 25@@-2h @
DVJn;X^T:
XP?)xDr8
//停止文件下载 _aJKt3GQ
public void siteStop() MX.?tN#F|H
{ |{_>H'
bStop = true; =q`T|9v
for(int i=0;i<nStartPos.length;i++) jp^Sw|
fileSplitterFetch.splitterStop(); 7?y7fwER
*-{|m1P
~P;A 9A(k
} Zj1bG{G=i
} =2ED w_5E
//负责部分文件的抓取 (oG.A
**FileSplitterFetch.java @2*Q*
*/ /SQ/$`1{
package NetFox; y\Utm$)j
8F@Sy,D
%H,s~IU
import java.io.*; 4-Jwy
import java.net.*; Re %dNxJ=
x}V&v?1{5
w*;"@2y;eY
public class FileSplitterFetch extends Thread { $$"G1<EZ
3JkdPh
a60rJ#GD
String sURL; //File URL aql8Or1[
long nStartPos; //File Snippet Start Position 6 .)Xeb"
long nEndPos; //File Snippet End Position %\n|2*r
int nThreadID; //Thread's ID `Pc<0*`a
boolean bDownOver = false; //Downing is over CH;U_b
boolean bStop = false; //Stop identical g|7o1{
FileAccessI fileAccessI = null; //File Access interface r\Kcg~D>
r@bh,U$
HEIg_6sb
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Au}l^&,zN
{ j0V/\Ep)T<
this.sURL = sURL; V/kndV[j
this.nStartPos = nStart; PLMC<4$s
this.nEndPos = nEnd; 5b*knN>
nThreadID = id; IF\ @uo`
fileAccessI = new FileAccessI(sName,nStartPos);//定位 slUi)@b
} jX(hBnGW
:Jv5Flxl
0K26\1
public void run() u*rP8GuS
{ z ynu0X
while(nStartPos < nEndPos && !bStop) 7v)p\#-
{ '%XYJr:H[
zB~<@
ahy6a,)K~
try{ a#;;0R $
URL url = new URL(sURL); 5g/,VMe
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \=bKuP(it
httpConnection.setRequestProperty("User-Agent","NetFox"); .g\Oj0Cbxh
String sProperty = "bytes="+nStartPos+"-"; .9PT)^2
httpConnection.setRequestProperty("RANGE",sProperty); wWiYxBeN
Utility.log(sProperty); v$Hz)J.01
&b}g.)RI
0doJF@H
InputStream input = httpConnection.getInputStream(); V K 7
//logResponseHead(httpConnection); q!@!eC[b
oW6Hufu+o
V-n{=8s
byte[] b = new byte[1024]; 'wG1un;t
int nRead; UU MB"3e
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) "wTCO1
{ bvB',yBZ
nStartPos += fileAccessI.write(b,0,nRead); Rqp#-04*W
//if(nThreadID == 1) ipbhjK$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3IlVSR^py
} fx[&"$X
X.k8w\~
zIjfxK
Utility.log("Thread " + nThreadID + " is over!"); fs&$?mHL){
bDownOver = true; XGH:'^o_
//nPos = fileAccessI.write (b,0,nRead); PQ[?zNrSV
} F}ATY!
catch(Exception e){e.printStackTrace ();} ,}gJY^X+
} >19s:+
} e&d$kUJrq
(EY@{'.&
n9}BT^4 v
//打印回应的头信息 ;M4[Liw~O
public void logResponseHead(HttpURLConnection con) ]Z8u0YtM)
{ PENB5+1OK
for(int i=1;;i++) ,.cR@5qI
{ wGKxT ap
String header=con.getHeaderFieldKey(i); 76)"uqv1x
if(header!=null) ":M]3.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); AG=PbY9
Utility.log(header+" : "+con.getHeaderField(header)); 4=Ru{ewRV
else T :d+Qz\
break; u@#%SX
} `@],J
} @ztT1?!e
BoYY^ih
L,y q=%h|
public void splitterStop() [07E-TT2U
{ @Xl(A]w%!
bStop = true; 'WP~-}(
} _uMG?Sbx
aO&{.DO2
"I/05k K
} S*h^7?Bu
*af\U3kx
y 2> 93m
/* N{HAWB{
**FileAccess.java t,|Apl]
*//文件访问(定位，写) >jhcSvM6
package NetFox; Q:megU'u
import java.io.*; jsE8=zZs
3Z9Yzv)A
_.; PLq~0
public class FileAccessI implements Serializable{ 0j!3\=P$
M1-tRF
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Y:TfD{Xgc
RandomAccessFile oSavedFile; *eIX"&ba
long nPos; xB Wl|j
<$z[pw<
>ceC8"}J5M
public FileAccessI() throws IOException zl:by?
{ 8fP2qj0
this("",0); 9m$"B*&6G
} ?5nEmG|kO
Eb4NPWo
:a;F3NJ
public FileAccessI(String sName,long nPos) throws IOException 0q"4\#4l
{ MSS[-}
oSavedFile = new RandomAccessFile(sName,"rw"); ~Yk^(hl2
this.nPos = nPos; ?m]vk|>
oSavedFile.seek(nPos); SqPqL<,e
} c8X;4 My
w gS'/
@iuX~QA[9
public synchronized int write(byte[] b,int nStart,int nLen) #ay/VlD@
{ O^8ZnN_+
int n = -1; Gkuqe3
try{ -\f7qRW^U
oSavedFile.write(b,nStart,nLen); VU,G.eLW
n = nLen; .>R`#@+I
} /ZV2f3;t
catch(IOException e) jSE)&K4nI
{ z)C/U
e.printStackTrace (); i&>^"_4rc
} y7F |v8bq
A)]&L`s
ZMgsuzg
return n; Zo&i0%S\E
} .yy*[56X
xcW\U^1d
K{DC{yLu
} ;99oJD,
r 1r@TG\
ny13+Q`^
/* s oY\6mHio
**SiteInfoBean.java Hj{.{V
*/ HfSx*@\s
package NetFox; t~o"x.
,.9lz
3Y38lP:>h
public class SiteInfoBean { B=d<L^
uG7]s]Wdz;
t7-]OY7%w_
private String sSiteURL; //Site's URL 3XQa%|N(
private String sFilePath; //Saved File's Path PSq?8.
private String sFileName; //Saved File's Name LhLAQ2~
private int nSplitter; //Count of Splited Downloading File #b;?:.m\=
y`n?f|nf
doL-G?8B
public SiteInfoBean() (%L/|F_
{//nSplitter的缺省值为5 oIick
//default value of nSplitter is 5 jXA/G%:[
this("","","",5); D{B?2}X
} ~7ZZb*].(
`qhT
$4g{4-)
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $t%IJT
{ jyIIE7.I"
sSiteURL= sURL; 0V<kpC,4
sFilePath = sPath; V_~lME
sFileName = sName; 0C :8X
this.nSplitter = nSpiltter; z9S (<
Py v>
ys=} V|
} |-V:#1wR.]
(5!'42
}lp37,
public String getSSiteURL() B%\&Q@X
{ bI ;I<Qa
return sSiteURL; ,7@\e&/&
} "YI,
eX#.Zt]
nvndgeSy
public void setSSiteURL(String value) yq;[1O_9C
{ VrRF2(Kn?
sSiteURL = value; &YY`XEG59O
} GV0@We~
PI*@.kqR-
];w}?LFb
public String getSFilePath() .*`^dt
{ r&8aB85
return sFilePath; ."ZG0Zg
} ^ELZ35=qZ
E:8*o7
Qq:}Z7 H
public void setSFilePath(String value) #l}Fk)dj
{ q~> +x?30
sFilePath = value; fhN\AjB6Td
} nRBS&&V
op`9(=DJ]
:8@)W<>%
public String getSFileName() y\_+,G0
{ jm%s#`)g
return sFileName; TQck$&
} {*+J`H_G2a
`D%i`"~Lf&
-OJ<Lf+"=
public void setSFileName(String value) *>W<n1r@]
{ GPLop/6
sFileName = value; GU>j8.
} -& (iU#W
BO*)cLQ
;l!<A
public int getNSplitter() zp8x/,gwF
{ 2!-Q!c`y
return nSplitter; \Ki3ls
} d;dT4vx$[M
8zHx$g
H8w[{'Mei
public void setNSplitter(int nCount) DRm`y>.
{ 0qNk.1pv
nSplitter = nCount; zlEI_th:~
} lUjZ=3"'
} /b>xQ.G
YT8q0BR]
/(8"]f/
/* 3T.V*&
**Utility.java 05H:ZrUV
*/ 1_{e*=/y
package NetFox; }+m4(lpl
)zO|m7
?S& yF
public class Utility { J#C4A]A
nZi&`HjQ
#+D][LH4
public Utility() Kkq-x'gt^
{ 3\RD%[}
^J>m4`
{,5.svO
} >8{w0hh;
xKE=$SV(
//线程睡眠 ;!f~
public static void sleep(int nSecond) c&bhb[
{ uT=r*p(v
try{ ahgP"Qz
Thread.sleep(nSecond); ZgEV-.>P
} a^LckHPI>
catch(Exception e) dCM&Yf}K
{ >QYx9`x&
e.printStackTrace (); ZhCd**
} pmBN?<
} B ZU@W%E
XE_Lz2H`
//日志 7ucm1
public static void log(String sMsg) awR !=\
{ xkFa
System.err.println(sMsg); yHE\Q
} T"htWo{v>
.Bkfe{^
to).PI?
public static void log(int sMsg) sHPAr}14
{ #tg\ bb
System.err.println(sMsg); 9LPXhxNwB
} 'eBD/w5U
} \y271}'
.s4vJKK0
L44|/~
/* *2/qm:gB
**TestMethod.java V?yQm4
*/ Da)p%E>Q
package NetFox; ,? <;zq
|in>`:qk
]0<K^OIY
public class TestMethod { ~Qif-|[V
`vzMuL;
R%r25_8
public TestMethod() G)YmaHeI;[
{ ///xx/weblogic60b2_win.exe ncadVheKt
try{ oMAUR "
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); I-8I/RRkmP
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); +cXi|Zf
SiteFileFetch fileFetch = new SiteFileFetch(bean); ,#BD/dF
fileFetch.start(); G[ns^
} 4xT /8>v2|
catch(Exception e){e.printStackTrace ();} :mDOqlXW/
WYRC_U7
0J[B3JO@M
} .!^OmT,u
13 L&f\b
wKdWE`|y
public static void main(String[] args) ~pH!.|k-&
{ NApy(e5%
new TestMethod(); G"3KYBN>
} z7BFkZ6+
} xX<T5Ls
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