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)); "]dNN{Wka
} eJB !|
for(int i=0;i<nEndPos.length-1;i++) [4qx+ypT
{ ~ l'dpg
nEndPos = nStartPos[i+1]; lkWID
} (bIg6_U7\
nEndPos[nEndPos.length-1] = nFileLength; 2sJj -3J
} 94umk*ib
} +@Oo)#V|.
fXPD^}?Ux4
a_UVb'z
//启动子线程 k:Iz>3O3]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; f*VBSg[`
for(int i=0;i<nStartPos.length;i++) BTwLx-p9t
{ m8q3Pp
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 7[wHNJ7)r
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 3%<Uq%pJ
nStartPos,nEndPos,i); L,&R0gxi
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H*DWDJxmV
fileSplitterFetch.start(); :RsO$@0G
} l@8UL</W
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), F j_r n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); H1(Zzn1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", XCNfogl
nEndPos = " + nFileLength); AZ7
// fileSplitterFetch[nPos.length-1].start(); Nj2f?',;U
o5(p&:1M
8:%=@p>$
//等待子线程结束 ?qeBgkL(B^
//int count = 0; Md9b_&'
//是否结束while循环 smpz/1U
boolean breakWhile = false; :&#HrD[KT
v(vLk\K7
*TpzX y
while(!bStop) P<+5So0
{ KWVEAHIn
write_nPos(); un4q,Ac~0
Utility.sleep(500); %rpJZ t
breakWhile = true; F)we^'X
D:9/;9V
#Y3:~dmJ-
for(int i=0;i<nStartPos.length;i++) ,"PKGd]^
{ 47R4gs#W
if(!fileSplitterFetch.bDownOver) x~Egax
{ m@hmu}qz-
breakWhile = false; WKf->W
break; K|-?1)Um
} pSQ)DqW
} y9?~^pTx
if(breakWhile) uaMf3HeYV
break; B5>1T[T'-
>^#OtFHuT)
TO.71x|
//count++; H+:SL $+<o
//if(count>4) pu(a&0
// siteStop(); 03ol!|X"9
} -e"~UDq`
yub|
D|W^PR:@h
System.err.println("文件下载结束！"); oT7=
} SbNs#
catch(Exception e){e.printStackTrace ();} 6&o9mc\I
} ?UC3ES
_pSCv:3T
=&QC&CqEi
//获得文件长度 ~Qzb<^9]
public long getFileSize() W+[XNIg5
{ Ca[H<nyj
int nFileLength = -1; >E;-asD
try{ 4Gl0h'!(
URL url = new URL(siteInfoBean.getSSiteURL()); EG<YxNX,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j rX.e
httpConnection.setRequestProperty("User-Agent","NetFox"); MP|J 0=H5
(9_~R^='y
cqzd9L6=
int responseCode=httpConnection.getResponseCode(); `6KTQk'
if(responseCode>=400) ;b=3iT-2"
{ adG=L9 "n
processErrorCode(responseCode); 0h~Iua5
return -2; //-2 represent access is error yUb$EMo\
} xjHOrr OQ
8r^~`rL
pyEi@L1p
String sHeader; T:ye2yg
/"A)}>a
S/}6AX#F4
for(int i=1;;i++) :DP%>H|
{ B3V:?#
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <qD/ #$
//Utility.log(in.readLine()); J:
sHeader=httpConnection.getHeaderFieldKey(i); ~]HeoQK
if(sHeader!=null) 6iwIEb
{ z4f\0uQ
if(sHeader.equals("Content-Length")) x0^O?UR
{ x!klnpGp
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 2c>eMfa
break; 3.q%?S}*
} 1eC1Cyw
} uJz<:/rwZ-
else O)ks
break; 6"^Yn.
} wB6ILTu1
} ViV"+b#gu
catch(IOException e){e.printStackTrace ();} }."3&u't
catch(Exception e){e.printStackTrace ();} fsU6o4
G% wVQ|1
7XKPC+)1ya
Utility.log(nFileLength); Vv=/{31
sY4sq5'!
%T]NM3|U
return nFileLength; IwC4fcZX6
} 0be1aY;m&
8spoDb.S
2@``=0z
//保存下载信息（文件指针位置） =M"H~;f]
private void write_nPos() `UFRv
{ tlw$/tMa
try{ ]>R|4K_
output = new DataOutputStream(new FileOutputStream(tmpFile)); yT Pi/=G
output.writeInt(nStartPos.length); (are2!Oq
for(int i=0;i<nStartPos.length;i++) !w['@x.
{ +0U{CmH
// output.writeLong(nPos); zk8 o[4
output.writeLong(fileSplitterFetch.nStartPos); rrK&XP&
output.writeLong(fileSplitterFetch.nEndPos); laX(?{_
} >$=-0?.
output.close(); ]3tg|?%B
} ;SAurG$
catch(IOException e){e.printStackTrace ();} uU v yZ
catch(Exception e){e.printStackTrace ();} &fJ92v?%^S
} ~F8M_
`IQ01FuP
-"qw5Y_oF?
//读取保存的下载信息（文件指针位置） 7;dTQ.%n
private void read_nPos() y9d[-j ;w
{ mA|&K8H
try{ y:Xs/RS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); L/1zG/@
int nCount = input.readInt(); l2uh"!
nStartPos = new long[nCount]; (vm&&a@
nEndPos = new long[nCount]; fMe "r*SU
for(int i=0;i<nStartPos.length;i++) ugexkdgM
{ Xg:w;#r,
nStartPos = input.readLong(); *<k8H5z8]
nEndPos = input.readLong(); ;K<e]RI;?
} F&US-ce:M
input.close(); fUQuEh5_
} q[4{Xh
catch(IOException e){e.printStackTrace ();} \F]X!#&+
catch(Exception e){e.printStackTrace ();} )(~s-x^\z@
} oJC-?
OgJd^
su]CaHU
private void processErrorCode(int nErrorCode) lqFDX d
{ ;cQhs7m(9
System.err.println("Error Code : " + nErrorCode); NpV#zzE
} (Fq|hgOA>M
s(*LV2fa
:5!>h8p;
//停止文件下载 Jlw<%}r
public void siteStop() 9{{QdN8
{ 2N_8ahc
bStop = true; =}N&c4I[j
for(int i=0;i<nStartPos.length;i++) Gt4| ]
fileSplitterFetch.splitterStop(); K#bdb
$o rN>M42
}gL:"C"~
} (.Hiee43
} bJc<FL<E
//负责部分文件的抓取 L><# I
**FileSplitterFetch.java WP,Ll\K)7
*/ rU?sUm,ch
package NetFox; / fBi9=}+
q{v:T}Q|A
D=}UKd
import java.io.*; %H=d_Nm{
import java.net.*; C?@vBM}
n_;qB7,,
N3?hyR<T
public class FileSplitterFetch extends Thread { SN!TE,=I
s*`_Ka57]~
>ZMB}pt`
String sURL; //File URL A4RA5N/}
long nStartPos; //File Snippet Start Position XWH{+c"
long nEndPos; //File Snippet End Position Il(p!l<Xz#
int nThreadID; //Thread's ID om%L>zfB
boolean bDownOver = false; //Downing is over );T0n
boolean bStop = false; //Stop identical C^ngdba\
FileAccessI fileAccessI = null; //File Access interface y]|Hrx
""cnZZ5)
-dXlGOD+C
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ? b;_T,S[
{ (_S`9Z8=
this.sURL = sURL; x] [/9e
this.nStartPos = nStart; u6o:~=WwM
this.nEndPos = nEnd; RlH|G
nThreadID = id; *?|LE C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \]Nlka
} VC%{qal;q
~R7F[R
SMHQo/c r
public void run() MD(?Wh
{ [JAHPy=+w
while(nStartPos < nEndPos && !bStop) >TSPEvWc
{ eF]`?AeWQ
P{YUW~
Vfkm{*t)
try{ hV5Aw;7C
URL url = new URL(sURL); O <;Au|>*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kTQ.7mo/\'
httpConnection.setRequestProperty("User-Agent","NetFox"); USgZ%xk2
String sProperty = "bytes="+nStartPos+"-"; ^0A}iJL
httpConnection.setRequestProperty("RANGE",sProperty); 9Q{-4yF9k
Utility.log(sProperty); yV=Ku
p=F!)TnJN
yo\R[i(
InputStream input = httpConnection.getInputStream(); 7!%/vO0m
//logResponseHead(httpConnection); E'3=qTbiD
*v1M^grKd
2aQR#lcv
byte[] b = new byte[1024]; B|%(0j8
int nRead; j8k5B"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >b2j j+8
{ Jg3OMUt
nStartPos += fileAccessI.write(b,0,nRead); FT.6^)-
//if(nThreadID == 1) }DH3_M!
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }^|g|xl!
} uTsxSkHb/
s"u6po.'
[ j'L*j
Utility.log("Thread " + nThreadID + " is over!"); y$,K^f
bDownOver = true; =MQpYX
//nPos = fileAccessI.write (b,0,nRead); )xJCH9h
} SU,S1C_q8
catch(Exception e){e.printStackTrace ();} Z>=IP-,>
} 1'.SHY|
} +Sz%2Q
t8vR9]n
L=`QF'Im
//打印回应的头信息 *nb `DR
public void logResponseHead(HttpURLConnection con) <2b&AF{En
{ f uzz3#
for(int i=1;;i++) )`,||sQ
{ f3,qDbQyJ
String header=con.getHeaderFieldKey(i); MA}~bfB
if(header!=null) m|K"I3W$
//responseHeaders.put(header,httpConnection.getHeaderField(header)); -Ky<P<@ezm
Utility.log(header+" : "+con.getHeaderField(header)); |.w'Z7(s
else _+c' z
break; )OjTn"
} i.QS(gM
} N=Q<mj;,
9f UD68Nob
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public void splitterStop() ;/ wl.'GA
{ g.L~Z1-
bStop = true; ^\<nOzU?
} \X3Q,\H @
JONfNb+
X#;n Gq)5
} h%4aL38
\!O3]k,r
UA>3,|gV1
/* n $Nw/Vm
**FileAccess.java KGM9 b
*//文件访问(定位，写) gMXs&`7P
package NetFox; _*&I[%I5
import java.io.*; j-~x==c-;
}j+Af["W?
g`7C1&U*T
public class FileAccessI implements Serializable{ 9Hu;CKs
^pB}eh.@U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 w\V1pu^6@
RandomAccessFile oSavedFile; ^$FNu~|K
long nPos; J&P{7a
Bb[WtT}=
RB\ Hl
public FileAccessI() throws IOException ]izrr
{ bEQy5AX
this("",0); %rFR:w`{
} PL/g@a^tY
z6IOVQ*r
X| !VjUH
public FileAccessI(String sName,long nPos) throws IOException M&QzsVH
{ ?xa70Pb{;
oSavedFile = new RandomAccessFile(sName,"rw"); eeVDU$*e=
this.nPos = nPos; /"+CH\) E
oSavedFile.seek(nPos); MQc<AfW3/
} N_:H kI6
bA_/6r)u
%IA1Y>`
public synchronized int write(byte[] b,int nStart,int nLen) }4uHT.)
{ MV{\:l}y
int n = -1; [Xa,|
try{ %fT%,( w}t
oSavedFile.write(b,nStart,nLen); -R]Iu\
n = nLen; vU,V[1^a
} &6feR#~A
catch(IOException e) bUzo>fm_
{ ,59G6o
e.printStackTrace (); '2S/FOb
} [X9T$7q#
DX2_}|$!
SD/=e3
return n; #ORZk6e
} IdS=lN$
'iM#iA8
"L0Q"t:
} (U{,D1?
Z5j\ M
[S~/lm
/* $+k|\+iJ
**SiteInfoBean.java CL|d>
*/ "[QQ(]={
package NetFox; uGmv`R_
c$.Zg=
N&uRL_X.
public class SiteInfoBean { 3 <A?
`K7UWtp
4-CGe
private String sSiteURL; //Site's URL SeV`RUO
private String sFilePath; //Saved File's Path 8aqH;|fG}
private String sFileName; //Saved File's Name K/YXLR +
private int nSplitter; //Count of Splited Downloading File +C}s"qrb@
|EGC1x]j=
rNK<p3=7)
public SiteInfoBean() }PXtwp13&u
{//nSplitter的缺省值为5 bA-/"'Vp9
//default value of nSplitter is 5 KqL+R$??"(
this("","","",5); S.zY0
} @tX8M[.eA
@+6cKP
.rwa=IW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) o5E5s9n
{ GI<3L K\
sSiteURL= sURL; 0{OafL8&l
sFilePath = sPath; %p(X*mVX
sFileName = sName; ~eyZH8&
this.nSplitter = nSpiltter; ,/YTW@N
N79?s)l:K
3Q#Tut
} Ez/>3:;
d4m@u$^1B
#AR$'TE#
public String getSSiteURL() DO 0
{ R0#'t+7^
return sSiteURL; dw-o71(1d
} k|^YYi=xF
h:AB`E1
-l~+cI\2
public void setSSiteURL(String value) NI:3hfs
{ eJ0Xfw%y%T
sSiteURL = value; G+1i~&uV
} ]i/Bq!d l
M+VAol}1
:'4",
public String getSFilePath() ;lQ>>[*
{ !{?<(6;t
return sFilePath; +,_%9v?3
} K,o&gY
o3X0c6uU
NdmwQJ7e"
public void setSFilePath(String value) uqM=/T^A
{ {pXqw'"1.
sFilePath = value; P#|}]oG%
} Ck:+F+7_v
_7;D0l
3Ct:AJeg
public String getSFileName() 6 u1|pX8
{ 4iv&!hAc;
return sFileName; zGwM# -
} oh7tE$"c
iOtf7.@
}OqP`B
public void setSFileName(String value) n= q7*<l
{ d/[kky}
sFileName = value; :rU,7`sE/
} 6@VgLa,
-br): }f
C{>dE:*K^
public int getNSplitter() fizL_`uMqb
{ iEx4va-j
return nSplitter; 25;(`Td5
} 2Z-QVwa*U
3*E] :l_
&W}6Xg(
public void setNSplitter(int nCount) mgTzwE_\
{ MnP+L'|
nSplitter = nCount; B2Kh~Xd
} %R<xe.X
} 8<{i=V*x4
\cdns;
T0@$6&b%\z
/* *mkVk7]c
**Utility.java WFTwFm6
*/ NpxgF<G
package NetFox; 9TZ6c
eVzZfB-=4}
r%9=75HA
public class Utility { Wjli(sT#-
$|N\(}R
?ph>:M
public Utility() MvTp%d.
{ x@@bC=iY$
6$K@s
3:>hHQi
} M}$Td_g
K,,'{j2#f
//线程睡眠 qFI19`?8E
public static void sleep(int nSecond) &YBZuq2?
{ kz G W/
try{ xkQT#K=i
Thread.sleep(nSecond); ~sdM~9@ '
} iZ4"@G:,
catch(Exception e) wlEK"kKU
{ DUwms"I,%
e.printStackTrace (); (o^?i2)g
} !gcea?I
} .vie#,la
pwRCfR)"X
//日志 JL[!8NyU
public static void log(String sMsg) Y8h 96
{ y[zjs^-vCv
System.err.println(sMsg); qCB{dp/
} XRTiC#6
C#B|^A_
i7e_~K
public static void log(int sMsg) oPVt qQ
{ s{*bFA Z1F
System.err.println(sMsg); i0Rj;E=:]
} S%e)br}
} P26"z))~d
}D-jTZlC
,YJn=9pTl
/* u'^kpr`y
**TestMethod.java +.gj/uy*
*/ =2YXh,i
package NetFox; HBZ6Pj
x<7?
;#^ o5ht
public class TestMethod { yq1G6hw
+|TXKhm{
v3G$9(NE;
public TestMethod() UY .-Qt
{ ///xx/weblogic60b2_win.exe p=\Q7<Z6d,
try{ qt6@]Y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); k9;t3-P
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); QP<.~^ao
SiteFileFetch fileFetch = new SiteFileFetch(bean); zN=s]b=/
fileFetch.start(); yMC6 Gvp
} c|K:oi,z
catch(Exception e){e.printStackTrace ();} 2%*\XPt)
2XEE/]^
li{!Jp5]1b
} C{+JrHV%h
TF80WMt
YI`BA`BQ8
public static void main(String[] args) BO8?{~i
{ [7NO !^
new TestMethod(); QKhGEW~G
} /,~g"y.;,
} h lSav?V_
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