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)); Y=4,d4uu
} ;/SM^&Y
for(int i=0;i<nEndPos.length-1;i++) K,^{|5'3q
{ \sF}NBNT@
nEndPos = nStartPos[i+1]; Srz.-,2PF
} !o&Mw:d
nEndPos[nEndPos.length-1] = nFileLength; Q/=L(_1l
} o_EXbS]C
} } CJQC
q0w5ADd
O.1Z3~r-N
//启动子线程 w-|i8%X
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ?4_^}B9
for(int i=0;i<nStartPos.length;i++) |jaUVE_2[
{ &|26x >
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ^C@uP9g
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), L$@^EENS
nStartPos,nEndPos,i); 6$b"tdP
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p(~>u'c
fileSplitterFetch.start(); +8Zt<snG
} ZsUxO%jP
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), :j vx-jQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?ae:9ZcH
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ZQnJTS+Rd
nEndPos = " + nFileLength); M&y!w
// fileSplitterFetch[nPos.length-1].start(); #=b_!~:%
((Ec:(:c
I [0od+K
//等待子线程结束 ]{nFB3vtB
//int count = 0; ,$sq]_t
//是否结束while循环 Sy'/%[+goJ
boolean breakWhile = false; ev#d1s|<S
iH( K[F /
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while(!bStop) *6q8kQsz^1
{ czb(&><
write_nPos(); QO7> XHn
Utility.sleep(500); Yq#I# 2RD
breakWhile = true; oFHVA!lqe
9ToM5oQ
q[1H=+
for(int i=0;i<nStartPos.length;i++) 1U~AupHE
{ d^Ra1@0"q2
if(!fileSplitterFetch.bDownOver) #d*mG =
{ rr*",a"}m
breakWhile = false; @|%t<{y^I
break; 0d:t$2~C
} ay'=M`uO_
} #2I[F
if(breakWhile) Fkz+Qz
break; R',|Jf=`
vP3Fb;
<=cj)
//count++; Cr4shdN34
//if(count>4) {mw,U[C
// siteStop(); ~DPg):cZ
} {j,bV6X
q uv`~qn
bI@+Or
System.err.println("文件下载结束！"); ~VUNN[
} PFG):i-?
catch(Exception e){e.printStackTrace ();} JQsS=m7Et
} o]MQ)\r
S]9:3~
phbdV8$L
//获得文件长度 t_3)}
public long getFileSize() 8S@ ~^D
{ @+Berb
int nFileLength = -1; EFf<|v
try{ mh.0% 9`9
URL url = new URL(siteInfoBean.getSSiteURL()); ~ceGx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); gJ c5Y
httpConnection.setRequestProperty("User-Agent","NetFox"); mv SNKS
=a?l@dI]
{.H}+@0
int responseCode=httpConnection.getResponseCode(); vp4!p~C{
if(responseCode>=400) 5D-xm$8C
{ 6H VS0
processErrorCode(responseCode); W8yr06{]
return -2; //-2 represent access is error 2[9hl@=%
} |j^>6nE
(Y, @-V
t{!}^{ "5
String sHeader; emw3cQ
E^1uZI\z
RX=C)q2c
for(int i=1;;i++) {^"c>'R
{ }N2T/U
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )`-9WCd&
//Utility.log(in.readLine()); A7+eWg{
sHeader=httpConnection.getHeaderFieldKey(i); r&1N8o
if(sHeader!=null) e@Z(z^V
{ 6N~~:Gt
if(sHeader.equals("Content-Length")) yXppu[=
{ x nWapG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5U3="L
break; k2<VUeW5
} 2p@Rr7
} Qgo0uuM
else 3UD_2[aqN(
break; f Nm Sx
} e0j*e7$
} k-Jj k3
catch(IOException e){e.printStackTrace ();} g?^o++
catch(Exception e){e.printStackTrace ();} HP. j.
AJ^9[j}
pL.r 9T.
Utility.log(nFileLength); zJ3{!E}`v
&Zd{ElM
"p#mNc
return nFileLength; hKQT,
} b&HA_G4
!ygh`]6V
;|soc:aH
//保存下载信息（文件指针位置） 2B=yT8
private void write_nPos() [% |i
{ @]Iku6d-
try{ Rc0OEs%7P
output = new DataOutputStream(new FileOutputStream(tmpFile)); *1ku2e]z
output.writeInt(nStartPos.length); #kA/,qyM
for(int i=0;i<nStartPos.length;i++) Sw%=/g
{ SL pd~ZC?
// output.writeLong(nPos); Z7K;~*
output.writeLong(fileSplitterFetch.nStartPos); vs7Hg)F
output.writeLong(fileSplitterFetch.nEndPos); C[& \Xq
} EtcAU}9
output.close(); KNQX\-=
} b0PF7PEEQ
catch(IOException e){e.printStackTrace ();} oSx]wZZ
catch(Exception e){e.printStackTrace ();} _9Iz'-LgB
} BNQ~O^R0
&=<x&4H+
:f 1*-y
//读取保存的下载信息（文件指针位置） IObGmc
private void read_nPos() QC \8Zy
{ dL |D
try{ ,K+K`"Oy
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (/v(.t
int nCount = input.readInt(); XlV#)JX
nStartPos = new long[nCount]; 8"N<g'Yl,
nEndPos = new long[nCount]; F.c,FR2
for(int i=0;i<nStartPos.length;i++) #J)sz,)(
{ \a<qI
nStartPos = input.readLong(); \gDf&I
nEndPos = input.readLong(); jC@$D*"J
} ou6yi; l%
input.close(); @4sv(HyDY
} l<(MC R*
catch(IOException e){e.printStackTrace ();} 3RXq/E
catch(Exception e){e.printStackTrace ();} oa}-=hG
} g9<*+fV 2$
U$# ?Lw
9K@`n:Rw
private void processErrorCode(int nErrorCode) +Z/*=;
{ ?E^~z-
System.err.println("Error Code : " + nErrorCode); ;R@zf1UYA
} "n}J6
)ra_`Qdcf
Ldf<
//停止文件下载 :+bQPzL
public void siteStop() ,gUSW
{ &UEr4RK;I
bStop = true; g"`BNI]Qp
for(int i=0;i<nStartPos.length;i++) $!G7u<`na
fileSplitterFetch.splitterStop(); i`z1if6O
-,uTAk0+@
qTj7mUk
} 1}Tbp_
} ]- ")r
//负责部分文件的抓取 !)?n n3
**FileSplitterFetch.java P5P:_hr
*/ l"W9uS;\T
package NetFox; E<:XHjm
?k TVC
+j1s*}8
import java.io.*; 9]c2ub7
import java.net.*; g1@zk$
Q]S~H+eRy
I+rHb< P%
public class FileSplitterFetch extends Thread { _<6 ^r
s+#gH@c
IGV@tI
String sURL; //File URL 5k)QjZo
long nStartPos; //File Snippet Start Position B:\\aOEj
long nEndPos; //File Snippet End Position Pv17wUB
int nThreadID; //Thread's ID ~pO6C*"
boolean bDownOver = false; //Downing is over yH|[K=?S[
boolean bStop = false; //Stop identical !TA6-]1
FileAccessI fileAccessI = null; //File Access interface (+`pEDD{X
` .|JTm[
"9'~6b
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException GbUw:I
{ 5Ev9u),D+v
this.sURL = sURL; 'Ybd'|t{}
this.nStartPos = nStart; t3|If@T
this.nEndPos = nEnd; $sTbFY
nThreadID = id; ~Z9Eb|B
fileAccessI = new FileAccessI(sName,nStartPos);//定位 `O?Kftv*
} V7U&8UPb
eee77.@y-p
cY8XA6
public void run() 9t:F![rg
{ A'vQtlvKA
while(nStartPos < nEndPos && !bStop) ;IZ*o<_
{ VgD z:j
Y,w'Op
##+|zka!U
try{ IFcxyp
URL url = new URL(sURL); 8n+&tBq1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \3JZ=/
httpConnection.setRequestProperty("User-Agent","NetFox"); m\o<a|
String sProperty = "bytes="+nStartPos+"-"; %X7R_>.
httpConnection.setRequestProperty("RANGE",sProperty); K+ZJSfO6
Utility.log(sProperty); dw#K!,g
mFfw*,M
N[~{'i
InputStream input = httpConnection.getInputStream(); BgRfy2:
//logResponseHead(httpConnection); $&&mGD;?K
{; #u~e(W
H=Scrvfx
byte[] b = new byte[1024]; m?'H7cFR
int nRead; )hs"P%Zg
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6_]-&&Nr
{ 4Vl_vTz{i
nStartPos += fileAccessI.write(b,0,nRead); eG&\b-%
//if(nThreadID == 1) @ol=gBU
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2l]*><q|
} @32~#0a
3*)<Y}Tc
$mdmuUIy-3
Utility.log("Thread " + nThreadID + " is over!"); R[KF${X4
bDownOver = true; zmH8^:-x
//nPos = fileAccessI.write (b,0,nRead); jBZlNEw
} QZ?#ixvJ
catch(Exception e){e.printStackTrace ();} ;wo
} > %h7)}U
} % `Q[?(z
iO1ir+B\
;;e\"%}@=q
//打印回应的头信息 KZy2c6XO;
public void logResponseHead(HttpURLConnection con) ~puXZCatN
{ jz,Mm,Gi
for(int i=1;;i++) 7k,pUC-w7c
{ ,;;7+|`
String header=con.getHeaderFieldKey(i); 1(%9)).K
if(header!=null) p]h;M
//responseHeaders.put(header,httpConnection.getHeaderField(header)); i7$4i|
Utility.log(header+" : "+con.getHeaderField(header)); @Wgd(Ezd
else Lzmdy0!'
break; H#H@AY3Y
} er@"4R0
} ?QA![
F6 mc<n
PLD&/SgP*
public void splitterStop() kw)("SQ
{ bfo..f-0/Y
bStop = true; v.iHgh
} r-^FM~Jp
?,s]5
yP$@~L[!
} J]&^A$
gu?e%]X3
y8*MNw
/* jfmHc(fX4
**FileAccess.java a ?D]]0%
*//文件访问(定位，写) zT<fTFJ1
package NetFox; I=aoP}_
import java.io.*; 6/-]
*vy^=Yea
f3yH4r?;w
public class FileAccessI implements Serializable{ U ?iw
E_q/*}]pE
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L hp
RandomAccessFile oSavedFile; x,wXR=H
long nPos; V52>K$j
rR Kbs@1M
%G0J]QY{(x
public FileAccessI() throws IOException ;R5@]Hg6q
{ Vz.G!*>Dg
this("",0); ;X_bDiG$
} I+oe{#:.
[8C|v61Y
vHJOpQmt~
public FileAccessI(String sName,long nPos) throws IOException F u>
{ vYFtw L`
oSavedFile = new RandomAccessFile(sName,"rw"); @%lkRU)
this.nPos = nPos; gB _/(
oSavedFile.seek(nPos); 1JQ5bB"
} kM6i{{Q
J#.f%VJ
*wk?{ U
public synchronized int write(byte[] b,int nStart,int nLen) 2xLEB&
{ 3Pu8IXW
int n = -1; # &,W x
try{ =Bg $OX
oSavedFile.write(b,nStart,nLen); #B!|sXC
n = nLen; n~"qbtp}
} BGd# \2
catch(IOException e) Bd'X~Vj<
{ ?"F9~vx&G
e.printStackTrace (); ol0i^d*9F
} ^ps6\>=0cW
&Fiesi!tET
W [*Go
return n; Ln'y 3~@
} _sb~eB~<(
i:a*6b.U@N
zif&;)wV/
} @T"-%L8PL
[psZc'q
dhX$b!DA
/* ^h$^j
**SiteInfoBean.java [vGkr" =
*/ O~Jm<
package NetFox; <x8I<K
&4O2uEW0
YpOcLxFL
public class SiteInfoBean { 5cvvdO*C0
+\doF
|(%=zb=?X
private String sSiteURL; //Site's URL tk)JE^'
private String sFilePath; //Saved File's Path nTtE+~u
private String sFileName; //Saved File's Name yk0tA
private int nSplitter; //Count of Splited Downloading File pG6?"*Fz;
|oWl9j]Z
>'lvZt
public SiteInfoBean() xfF;u9$;
{//nSplitter的缺省值为5 tj?%{L
//default value of nSplitter is 5 pCf9"LLer
this("","","",5); "ejsz&n
} )3 I~6ar
O#<F"e;$
`h|Y0x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) cP",szcY
{ Dm@h'*
sSiteURL= sURL; Z0/$XS9|h;
sFilePath = sPath; CnpQdI
sFileName = sName; fsl ZJE
this.nSplitter = nSpiltter; ~.tl7wKkR/
^e]O-,UBk
0HO'%'Ga*
} csd9[=HW/Q
x8xz33
<NEz{1Z
public String getSSiteURL() 85f:!p
{ 5DpvMhc_
return sSiteURL; !kG|BJ$j
} naro
v.&c1hKHb
dB)-qL8,2
public void setSSiteURL(String value) ?I8r2M]
{ uHsLlfTn
sSiteURL = value; MK-+[K
} i[?VF\Y(
=9Vo[
r$1b=m,0d
public String getSFilePath() S"VO@)d
{ G|*&owJ
return sFilePath; Ma'#5)D
} C B`7KK
[8<0Q_?,
Qgf\"s
public void setSFilePath(String value) Ge @qvP_
{ Rt5,/Q0
sFilePath = value; i)]f0F
} P(s:+
VJ8'T"^Hf
ny%$BQM=
public String getSFileName() (j~T7og
{ =:Yrb2gP_\
return sFileName; VP~(;H5%
} !7f,gvk
mrq,kwM
_s+G02/q1
public void setSFileName(String value) cV"Ov@_.k
{ v8WT?%
sFileName = value; 2cO6'?b
} (&1.!R[X
]bAVOKm-
=]5f\f6
public int getNSplitter() +J85Re `
{ Sgr. V)
return nSplitter; ^D]J68)#a
} blWtC/!Aq;
H|0-Al.{
eIEL';N6
public void setNSplitter(int nCount) W':b6}?
{ ,>01Cs=t8
nSplitter = nCount; x#5vdBf
} %-]a[qf3
} +?W4ac1
+0 }_X
[!>9K}z,=
/* f~*7hv\
**Utility.java `dD_"Hdt
*/ '=O1n H<
package NetFox; 8{]nS8i
@ze2'56F}
Q lA?dXQ
public class Utility { @)x*62r+
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3;FV^V'
public Utility() 5]GgjQ
{ -Bl^TT
BsA'r+ho?H
]kXWeY<
} AN6Q~%,
:\I*_00!
//线程睡眠 ]DU?N7J
public static void sleep(int nSecond) _Rb2jq(&0
{ ML MetRP
try{ ,NvXpN
Thread.sleep(nSecond); 7p hf
} .heU Ir,
catch(Exception e) '!ks $}$`h
{ 0)cSm"s
e.printStackTrace (); j:qexhtho
} ^%!SKhRIK
} ";7xE#jRk
[=BMvP5
//日志 WF-jy7+
public static void log(String sMsg) r{t6Vv2J
{ L&y"oAp<
System.err.println(sMsg); &PH:J*?C}
} "OA{[)fw"
!zm;C@}ln
4;W{#jk
public static void log(int sMsg) M|j=J{r
{ Cl9rJ oT
System.err.println(sMsg); ^-Ygh[x
} _yUYEq<`
} S6_:\Q
a$h^<D ^
]j>`BK>FE
/* QxA( *1
**TestMethod.java 83I 5n&)
*/ %k32:qe
package NetFox; AD^I1]2f
oPF]]Imu
5y 5Dn!`
public class TestMethod { $|@vmv0
m(?{#aaq
b- e
public TestMethod() W1M322]>L
{ ///xx/weblogic60b2_win.exe i721(1
try{ F81EZ/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); G'p322Bu
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); JB].ht
SiteFileFetch fileFetch = new SiteFileFetch(bean); @{q<"hT
fileFetch.start(); !zx8I7e4
} *!JB^5(H
catch(Exception e){e.printStackTrace ();} L@/IyQ[H1
5-$D<}Z
Z)$@1Q4P?1
} "g#%d
^r.CUhx)
p/RT*?<
public static void main(String[] args) OA=~i/n~
{ qljsoDG
new TestMethod(); :UP8nq
} 9M3"'^ {$
} DpvHIE:W
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