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)); `2}Mz9mk
} C?X^h{Tp
for(int i=0;i<nEndPos.length-1;i++) q.~_vS%
{ Kc0KCBd8];
nEndPos = nStartPos[i+1]; kWF, *@.B
} TVQ9"C
nEndPos[nEndPos.length-1] = nFileLength; J](AJkGzK
} 3g)pLW
} 7mt;qn?n
6>zO"9
Fq9AO~z
//启动子线程 PjDYdT[
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h>q&X4-
for(int i=0;i<nStartPos.length;i++) }c$Zlb
{ 6"z:s-V
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &h')snp:#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >q"mI6F
nStartPos,nEndPos,i); RlC|xj"l%
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O*X]oX
fileSplitterFetch.start(); MoavA 3`
} ljQru ^(u
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), zcy!YB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >]s|'HTxF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", QT&2&#Z
nEndPos = " + nFileLength); +q6/'ErN]m
// fileSplitterFetch[nPos.length-1].start(); ]haZT\
%?^IS&]Z
IyOb0WiEj
//等待子线程结束 8.bdN]zn
//int count = 0; lEh;MJ
//是否结束while循环 4Un(}P'
boolean breakWhile = false; S&q@M
Mnc9l ^
JN,4#,
while(!bStop) ^cn%]X#.
{ Il`35~a
write_nPos(); .]JGCTB3
Utility.sleep(500); tDJtsOL
breakWhile = true; TY"8.vd
f,9/Yg_
jZx.MBVy]
for(int i=0;i<nStartPos.length;i++) *?:V)!.2z
{ Uf4A9$R.G
if(!fileSplitterFetch.bDownOver) >^=upf/
{ *2P%731n5
breakWhile = false; \oA>%+]5
break; 3rBSwgRl
} !:]CKbG
} &@<Z7))
if(breakWhile) GHWi,' mr
break; ibAZ=RD
*eK\W00
"wy|gnQJ
//count++; yS'W ss
//if(count>4) K&3,J7&&
// siteStop(); ^ ~'&K e
} 8iA[w-Pv
}OL?k/w
IOhJL'r
System.err.println("文件下载结束！"); UuPXo66F]
} L7VDZCV
catch(Exception e){e.printStackTrace ();} XYj!nx{k,
} ])`w_y(>
%Ya%R@b}
]{^'{z$i
//获得文件长度 +Nn $
public long getFileSize() lJb1{\|.,
{ T+1:[bqK
int nFileLength = -1; G9v'a&
try{ :{BD/6
URL url = new URL(siteInfoBean.getSSiteURL()); {%Cb0Zh
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Vq-W|<7C=
httpConnection.setRequestProperty("User-Agent","NetFox"); <hkSbJF
]ie38tX$
B>C+qj@
int responseCode=httpConnection.getResponseCode(); =S+*=jA
if(responseCode>=400) Z(F['Zf
{ M~+}ss
processErrorCode(responseCode); xP/?E
return -2; //-2 represent access is error !>RDHu2n
} 71b0MHNkvv
E.LD1Pm0
aG_@--=
String sHeader; M$YU_RPl+
#!?jxfsFa
H?oBax:
for(int i=1;;i++) B!+rO~
{ h@AKfE!\~
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )SU\s+"M
//Utility.log(in.readLine()); /~~A2.=.
sHeader=httpConnection.getHeaderFieldKey(i); fVJlA
if(sHeader!=null) 4|U$ON?x
{ O"^3,-
if(sHeader.equals("Content-Length")) R.x^
{ vG'6?%38
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3-~*
break; _nwsIjsW
} u1 Z;n
} kx{LY`pY
else u:]c
break; QQI,$HId
} ;*u"hIl1/
} $|"Y|3&X
catch(IOException e){e.printStackTrace ();} ZNDn! Sj
catch(Exception e){e.printStackTrace ();} +}VaQ8ti4
_ck)yY?7
11VtC)
Utility.log(nFileLength); `^v=*&
NMs8^O|0
r{cmw`WA/P
return nFileLength; Nwwn #+
} )fy-]Ky *
r{>`"
f`<elWgc"
//保存下载信息（文件指针位置） 2x5^kN7
private void write_nPos() ,Iv eKk5W
{ ~k"r
try{ ^yLhL^Y
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^/~ZP?%]
output.writeInt(nStartPos.length); dvAG}<
for(int i=0;i<nStartPos.length;i++) #Mw 6>5}<
{ _^/k
// output.writeLong(nPos); 9\'JtZO
output.writeLong(fileSplitterFetch.nStartPos); r1axC%
output.writeLong(fileSplitterFetch.nEndPos); tgyW:<iv
} fZ aTckbE
output.close(); _lG|t6y
} Y1Q240
catch(IOException e){e.printStackTrace ();} k=W~ot&
catch(Exception e){e.printStackTrace ();} )-\C{>
} ]-j.\+(*
,B~5;/|
57wHo[CJ
//读取保存的下载信息（文件指针位置） 'aWqj+Wbh
private void read_nPos() $fCKK&Wy
{ LD*XNcE
try{ /8#e < p
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); T>hrKn.!D:
int nCount = input.readInt(); aPdEEqc\l
nStartPos = new long[nCount]; {j6$'v)0
nEndPos = new long[nCount]; <78*-Ob
for(int i=0;i<nStartPos.length;i++) 5jq @ nq6
{ kzk8b?rOA
nStartPos = input.readLong(); Wsb>3J
nEndPos = input.readLong(); 25PZ&^G8%
} J`]9n>G
input.close(); ;kI)j ?
} 4Ei8G]O $_
catch(IOException e){e.printStackTrace ();} t[r6jo7
catch(Exception e){e.printStackTrace ();} Sa[?B
} =X1oB,W{
9a2[_Wy
XJ!?>)N .
private void processErrorCode(int nErrorCode) Oq^t[X'
{ Z9G4in8
System.err.println("Error Code : " + nErrorCode); }a!ny
} .mHVJ5^:4\
enx+,[
.p=OAh<
//停止文件下载 SBy{sbx4&F
public void siteStop() F EUfskv
{ )K8^}L,
bStop = true; +Wl]1 c/
for(int i=0;i<nStartPos.length;i++) uO>x"D5tZ:
fileSplitterFetch.splitterStop(); :7M%/#Fy
l 88n*O
p()q)P
} 9Af nMD
} ~470LgpO1
//负责部分文件的抓取 **$kWbS
**FileSplitterFetch.java @d5$OpL$%
*/ J&Db-
package NetFox; ?)ct@,Ek$
.i {yW
2TG2<wqvE
import java.io.*; OMW]9E
import java.net.*; 2$o#b.
&q&~&j'[
.]H/u "d
public class FileSplitterFetch extends Thread { %+nM4)h
x<`^4|<
lVuBo&
String sURL; //File URL b<!' WpY-
long nStartPos; //File Snippet Start Position a@Vk(3Rx_
long nEndPos; //File Snippet End Position a ~YrQI-@
int nThreadID; //Thread's ID /!JxiGn
boolean bDownOver = false; //Downing is over sSf;j,7V
boolean bStop = false; //Stop identical yEMM@5W)8
FileAccessI fileAccessI = null; //File Access interface ^*YoNd_kpN
P*jiz@6
,PoG=W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \K9.]PfbI
{ LGw-cX #
this.sURL = sURL; H<}|n1w<
this.nStartPos = nStart; )Tieef*Q~
this.nEndPos = nEnd; k.7!)jL7
nThreadID = id; q44vI
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /0cm7[a?
} u$CN$ynS
cNT !}8h^
|)v}\-\#
public void run() xQ';$&
{ 5t-d+vB
while(nStartPos < nEndPos && !bStop) 6ddRFpe
{ bo/<3gR
o~9sO=-O
W[k rq_c-
try{ f[vm]1#
URL url = new URL(sURL); ]&;In,z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TQ:h[6v
httpConnection.setRequestProperty("User-Agent","NetFox"); 0i"2s}^+_
String sProperty = "bytes="+nStartPos+"-"; =E$bZe8
httpConnection.setRequestProperty("RANGE",sProperty); A9g/At_
Utility.log(sProperty); 33KCO
$tF\7.e@
~3-"1E>Rgy
InputStream input = httpConnection.getInputStream(); t^Lb}A#$4
//logResponseHead(httpConnection); nGwon8&]]
U.V/JbXX
3#x1(+c6
byte[] b = new byte[1024]; O8A(OfX
int nRead; (,ik:j
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) +=Q:g,kP
{ \D k >dE&I
nStartPos += fileAccessI.write(b,0,nRead); HL]J=Gh
//if(nThreadID == 1) ; wxmSX9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |'&$VzA
} 5Ok3y|cEx
x4PzP
]%I\FefT
Utility.log("Thread " + nThreadID + " is over!"); #?+[|RS|
bDownOver = true; FZ}^)u}o
//nPos = fileAccessI.write (b,0,nRead); N34-z|"q
} 4DDBf j
catch(Exception e){e.printStackTrace ();} E|>-7k")
} NV-l9
} CJh,-w{wJ"
/}2Y-GOU
F+*fim'NK
//打印回应的头信息 t9MCT$U
public void logResponseHead(HttpURLConnection con) l.]wBH#RS
{ T{^P
for(int i=1;;i++) r73W.&
{ l*]hUPJ
String header=con.getHeaderFieldKey(i); 5!S#}=f=
if(header!=null) gvc/Z <Y
//responseHeaders.put(header,httpConnection.getHeaderField(header)); +}1zw<
Utility.log(header+" : "+con.getHeaderField(header)); mI{Fs|9h
else JWaWOk(t=?
break; l53Q"ajG
} Ywv\9KL
} +."|Y3a
?9O#b1f N
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public void splitterStop() livKiX`
{ (J.Z+s$:2
bStop = true; pZK 1G
} [B`4I
!q,7@W3i
j24DL+
} LLT6*up$
1<Mb@t
< qab\M0W
/* ]P#W\LZp
**FileAccess.java :!Dm,PP%
*//文件访问(定位，写) :*h1ik4t
package NetFox; t2vm&jk
import java.io.*; Y>/_A%vQU
x7<NaMK\
!hM`Oe`S
public class FileAccessI implements Serializable{ ;-JFb$m
!ht2*8$lQ
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Wu<;QY($5
RandomAccessFile oSavedFile; @k)J i!7
long nPos; P7zUf
6M`gy|"(~
)eT>[['fm
public FileAccessI() throws IOException hu} vYA7ZH
{ :j .:t
this("",0); tY]?2u%)
} N>YSXh`W`y
/n(0w`
`p9N| V
public FileAccessI(String sName,long nPos) throws IOException V sxI
{ 'I+M*Iy
oSavedFile = new RandomAccessFile(sName,"rw"); Nu?A>Q
this.nPos = nPos; %*!6R:gAp
oSavedFile.seek(nPos); n"aF#HR?0d
} gm,AH85
i ]8bj5j{
Vt3*~Beb
public synchronized int write(byte[] b,int nStart,int nLen) ?wlRHVZ
{ yQ[;.<%v
int n = -1; 9XtO#!+48
try{ -`{W~yz
oSavedFile.write(b,nStart,nLen); *xpn-hCp<
n = nLen; _EP]|DTfr
} ~Gmt,l!b
catch(IOException e) 82ixv<B
{ o6;
e.printStackTrace (); <QFayZ$
} +>1?ck
t3?I4HQ
T%&vq6
return n; zj] g^c;
} 8<T~AU8'*
sRZ<c
F(."nUrf
} _0gdt4
,g}$u'A+d
"= %"@"<)
/* jUNt4
**SiteInfoBean.java ](Wa:U}Xs
*/ 2]9 2J
package NetFox; |n tWMm:(
^7? WR?!
_V1:'T8
public class SiteInfoBean { GRYw_}Aa
,{S $&g*
"ldd&><
private String sSiteURL; //Site's URL 4v_Hh<%
private String sFilePath; //Saved File's Path ,aUbB8
private String sFileName; //Saved File's Name 0fBwy/:
private int nSplitter; //Count of Splited Downloading File SPdEO3
hp/pm6
pO7OP"q1
public SiteInfoBean() vX6JjE!
{//nSplitter的缺省值为5 &PL=nI\)
//default value of nSplitter is 5 LFxk.-{=
this("","","",5); +%,oq]<[,
} LI3L~6A>
)P b$
h9imS\gfr
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) W!\%v"
{ kiN,N]-V
sSiteURL= sURL; Spx%`O<
sFilePath = sPath; r9N?z2X
sFileName = sName; v!ai_d^
this.nSplitter = nSpiltter; fU ;H
c CDT27@
|5dNJF8;Q
} 6Y\TVRR
W).Kq-
oz.z>+Q
public String getSSiteURL() bcy
{ v'?o#_La+
return sSiteURL; U7jDm>I
} ]nebL{}5
}T\.;$f
v@GhwL
public void setSSiteURL(String value) -(WRhBpw
{ 'v0rnIsI?
sSiteURL = value; T}msF
} N2}Y8aR~
;qUB[Kw
>lqo73gM9
public String getSFilePath() RV{%@1Pu
{ c-(dm:
return sFilePath; H<fi,"X^
} # }}6JM
r^msJ|k8[
Hc>yZ:c;
public void setSFilePath(String value) @|t]9
{ w0j'>4
sFilePath = value; Ag+B*
} UcB&pt&
"\}h
CEw%_U@8
public String getSFileName() .),9qz`
{ #prYZcHv:_
return sFileName; .5s58Hcg,
} D]"W|.6@
Da8gOZ
Xp06sl7 M
public void setSFileName(String value) ic!% }S?
{ 4[kyzz x
sFileName = value; yFmy
} o^(I+<el
uK(]@H7~!c
n CX{tqy
public int getNSplitter() eXnSH$uI
{ $,/E"G`
return nSplitter; N3\RXXY
} 3o>JJJ=]
^W@8KB
O:rfDO
public void setNSplitter(int nCount) {j`8XWLZZN
{ L;M@]
nSplitter = nCount; s1::\&`za
} )i:*r8*~
} &v;fK$=2C
.s4v*bng
T_UJ?W
/* pi#a!Quf\
**Utility.java u0=&_Q(=
*/ R6Md_t\
package NetFox; Vrlqje_Q
Vi^vG`L9
-u"|{5? '
public class Utility { w{L9-o3A
03zt^<
D~i5E9s5
public Utility() !Z\Gv1
{ 3`{ vx
W(Sni[c{
wM7Iu86
} "PN4{"`V
RkF^V(
//线程睡眠 $*N(feAs
public static void sleep(int nSecond) a;IOL
{ NV(jp'i~
try{ $]};EI#
Thread.sleep(nSecond); SKNHLE}
} Rsq EAdZw[
catch(Exception e) kjsj~jwvv
{ - (((y)!
e.printStackTrace (); ~Yl.(R
} TTa3DbFp%
} `5Z'8^
V?.=_T<
//日志 3!sZA?q
public static void log(String sMsg) $iy!:Did
{ y1}2hT0,
System.err.println(sMsg); +IbV
} 4B[pQlg
+eH`mI0f
n<FUaR>q}
public static void log(int sMsg) ZQ`4'|"
{ V6c8o2G;+
System.err.println(sMsg); ) ] Ro
} h~qvd--p0
} u0k'Jh]K
HfH_jnR*
9SA%'
/* %rrD+
**TestMethod.java %WR"qd&HSh
*/ {%k[Z9*tO
package NetFox; *5s*-^'#!
Z{l`X#':
`#!>}/m
public class TestMethod { 4:O.x#p
1GkoE
'CJ_&HR
public TestMethod() GoX<d{
{ ///xx/weblogic60b2_win.exe <1lB[:@%U
try{ 37?X@@Z=
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); >f^kp8`3{Y
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); I H#CaD
SiteFileFetch fileFetch = new SiteFileFetch(bean); .L1[Rv3
fileFetch.start(); KI*bWe
} seAEv0YWz
catch(Exception e){e.printStackTrace ();} <Pe'&u
#"TYk@whWf
jZmL7 V
} e&ZH 1^O
1TfFWlf[B
=Xid"$
public static void main(String[] args) jg%mWiKwK7
{ Oi~Dio_?
new TestMethod(); G[>CBh5
} (yuOY/~k/
} P<[) qq@;
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