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)); XZ<8M}Lg
} :Bi 4z(
for(int i=0;i<nEndPos.length-1;i++) tB`IBuy9!"
{ bO*hmDt
nEndPos = nStartPos[i+1]; v0(_4U]/
} =&^tfD
nEndPos[nEndPos.length-1] = nFileLength; 7AF6aog
} 7- |N&u
} uFuP%f!yY
?CldcxM#
( 6ucA
//启动子线程 sJMpF8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; WidLUv
for(int i=0;i<nStartPos.length;i++) VAp 1{
{ j_.tg7X
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), R5xV_;wD
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), CIVV"p`}
nStartPos,nEndPos,i); oA8A @,-L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h!`KX2~
fileSplitterFetch.start(); P?@o?
} p)?6~\F:
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Js(MzL
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); c`/kx
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Mp(;PbVD
nEndPos = " + nFileLength); ';m;K (g
// fileSplitterFetch[nPos.length-1].start(); :o:Z
1.5R`vKn]
S{Zf}8?6$
//等待子线程结束 iI3,q-LA
//int count = 0; t]T't='
//是否结束while循环 G[=;519
boolean breakWhile = false; 0./Rdf=-1j
`O!yt
Gr'|nR8
while(!bStop) NZ?dJ"eq7
{ UgD)O:xaU
write_nPos(); E)|Bl>
Utility.sleep(500); fOdX2{7m
breakWhile = true; owwWm1@
5lyHg{iqD
%~M#3Ywa
for(int i=0;i<nStartPos.length;i++) qfRrX"
{ .*Z#;3
if(!fileSplitterFetch.bDownOver) .EC~o
{ :m36{#
breakWhile = false; !$#5E1:\
break; 1k`gr&S
} 1Beh&pl^
} 2cwJ);Eg2
if(breakWhile) xIH= gK
break; 5=b6B=\*~
R,fAl"wMu
"bz.nE*
//count++; ND/oKM+?
//if(count>4) h gu\~}kD
// siteStop(); wYDdy gS
} )@<HG$#
|{RCvm
9v1Snr
System.err.println("文件下载结束！"); R+2~%|{d
} ],{M``]q
catch(Exception e){e.printStackTrace ();} 24sQon
} w_DaldK*
s<oT,SPt
PS0/Ok
//获得文件长度 %/BBl$~ji
public long getFileSize() 221}xhn5
{ b;nqhO[f}
int nFileLength = -1; P76gJ@#m
try{ wr~Qy4 ny
URL url = new URL(siteInfoBean.getSSiteURL()); [Fv_~F491
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); TmK8z
httpConnection.setRequestProperty("User-Agent","NetFox"); q\<NW%KtX
[ua[A;K
SwaMpNXL
int responseCode=httpConnection.getResponseCode(); phB d+zQc
if(responseCode>=400) JSx[V<7m
{ 7PwH&rI
processErrorCode(responseCode); Ocz21gl-?`
return -2; //-2 represent access is error D[6wMep^n
} *1T~ruNqa
)<Mo.
Wys$#pJ
String sHeader; #4!f/dWJp
l<'}`
foB&H;A4oC
for(int i=1;;i++) m)]|mYjju
{ )@] W=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); @1U6sQ
//Utility.log(in.readLine()); [z6P]eC7
sHeader=httpConnection.getHeaderFieldKey(i); Vt-V'`Y
if(sHeader!=null) eu?P6>urA
{ [{#n?BT
if(sHeader.equals("Content-Length")) ~M1T @Mv
{ HGi%b5:<=M
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Y![8-L|Q
break; n57mh5mixM
} B*P;*re
} =LEzcq>XO
else ;bL?uL
break; s.XxYXR\
} r{_1M>F D!
} >GzH_]
catch(IOException e){e.printStackTrace ();} 7[i&EPN
catch(Exception e){e.printStackTrace ();} qD/h/
|tz{Es<`B
_X@ Q`d
Utility.log(nFileLength); 88 ca
t{`-G*^
BqdGU-Q
return nFileLength; 9;rZ)QD
} ]7RK/Zu i
)q/brCq
xK4E+^ b
//保存下载信息（文件指针位置） |CK/-UG}
private void write_nPos() k^K%."INn
{ uKB V`I
try{ :qV|rih_Q
output = new DataOutputStream(new FileOutputStream(tmpFile)); >SS^qjh/
output.writeInt(nStartPos.length); A0Q1"b=
for(int i=0;i<nStartPos.length;i++) J7~Kjl
{ %o`Cp64`Q
// output.writeLong(nPos); |uX&T`7?-
output.writeLong(fileSplitterFetch.nStartPos); }.=@^-JBA5
output.writeLong(fileSplitterFetch.nEndPos); AJ6O>Euq
} }:1qK67S
output.close(); I*mBU^<9V
} =/4}!B/
catch(IOException e){e.printStackTrace ();} 84s:cO
catch(Exception e){e.printStackTrace ();} 2P{! n#"
} \lyHQ-gWhc
BZjL\{IW
W9bpKmc
//读取保存的下载信息（文件指针位置） w(ic$
private void read_nPos() w;J#+ik
{ JD AX^]
try{ KqNsCT+j
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); f917F.1I
int nCount = input.readInt(); 2d<`dQY{l3
nStartPos = new long[nCount]; Xob(4
nEndPos = new long[nCount]; D2io3Lo$ov
for(int i=0;i<nStartPos.length;i++) 1KJ[&jS ]
{ G {a;s-OA3
nStartPos = input.readLong(); 5RYrAzQo
nEndPos = input.readLong(); 1-R4A7+3
} Bma.Uln
input.close(); tMo=q7ig
} APU~y5vG (
catch(IOException e){e.printStackTrace ();} \tdYTb.
catch(Exception e){e.printStackTrace ();} '[bw7T
} "tj]mij2)G
[.;8GMW
ENf(E9O
private void processErrorCode(int nErrorCode) [kPl7[OL
{ h9~oS/%:
System.err.println("Error Code : " + nErrorCode); _cJ\A0h^
} x7xQrjE
C.se/\PE
5rJ7CfVq
//停止文件下载 _$oE'lat
public void siteStop() ~Q=^YZgn8
{ lO}I>yo}\
bStop = true; |8{\j*3
for(int i=0;i<nStartPos.length;i++) 2,.8oa(
fileSplitterFetch.splitterStop(); ,{Z!T5 |
3v)`` n@
G@<[fO|Iam
} Su'l &]
} w" A{R
//负责部分文件的抓取 @^HZTuP2;
**FileSplitterFetch.java Tb] h<S
*/ \x"BgLSE
package NetFox; \JNWL yw
K{FBrh
VxU{ZD~<Z"
import java.io.*; ,~NJ}4wP
import java.net.*; .;&4'ga4
i^rHZmT
mrlhj8W?!
public class FileSplitterFetch extends Thread { tpP68)<ns
0rc'SEl
jfZ)
String sURL; //File URL t<+gyAW
long nStartPos; //File Snippet Start Position -?ebkHe
long nEndPos; //File Snippet End Position @~IZ%lEQsD
int nThreadID; //Thread's ID BqOMg$<\[
boolean bDownOver = false; //Downing is over al4X}
boolean bStop = false; //Stop identical kB-<17
FileAccessI fileAccessI = null; //File Access interface m\K1Ex
A.<M*[{q
>a: 6umY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException z~;@Mo"*f
{ +@\=v}: F
this.sURL = sURL; IY|>'}UU#
this.nStartPos = nStart; t5S!j2E
this.nEndPos = nEnd; KU_""T
nThreadID = id; 85+w\KuEY
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ,6wGdaMR
} U#4>GO;A
a!;K+wL >
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public void run() yuF\YOA9
{ >W'"xK|:
while(nStartPos < nEndPos && !bStop) d*:J0J(
{ $XFFNE`%
p{w;y6e
,){WK|_
try{ dewN\
URL url = new URL(sURL); s18A
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8ZDWaq8^2N
httpConnection.setRequestProperty("User-Agent","NetFox"); |PLWF[+t8
String sProperty = "bytes="+nStartPos+"-"; "T6s;'k
httpConnection.setRequestProperty("RANGE",sProperty); ^i17MvT'
Utility.log(sProperty); #LG<o3An
N\x<'P4q
P)UpUMt;k
InputStream input = httpConnection.getInputStream(); _(KzjOMt
//logResponseHead(httpConnection); KocNJ TB
fyv S1_
/qXP\ a
byte[] b = new byte[1024]; E_K32)J-
int nRead; zHvW@A'F
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) .H5^N\V|
{ 0Y*Ag,S
nStartPos += fileAccessI.write(b,0,nRead); ,f[Oy:fr
//if(nThreadID == 1) ,v(ikPzd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); hj3wxH.}
} iD:TKB_r
-M`+hVs?
}M9I]\
Utility.log("Thread " + nThreadID + " is over!"); HH^yruP\}
bDownOver = true; >):>Pz%U
//nPos = fileAccessI.write (b,0,nRead); "^Vfo$q
} DcZ,a E]
catch(Exception e){e.printStackTrace ();} UFr5'T
} }/F9(m
} ]#J-itO
Z]^O=kX7k
%eE 6\f%g
//打印回应的头信息 D}bCMN<
public void logResponseHead(HttpURLConnection con) q_0,KOGW
{ a8Z{-=)
for(int i=1;;i++) WD#7Q&T(;
{ ks<+gL{K|i
String header=con.getHeaderFieldKey(i); *g 2N&U
if(header!=null) {7 nz:f
//responseHeaders.put(header,httpConnection.getHeaderField(header)); R,W w/D
Utility.log(header+" : "+con.getHeaderField(header)); 1zY"Uxp
else q]m$%>
break; hu-6V="^9
} h) W|~y@
} lf2(h4[1R
@86I|cY
H`8}w{ft&
public void splitterStop() rh6m
{ [u/Wh+
bStop = true; DgC;1U'
} W/<C$T4
93y!x}
lhJZPnx~
} 'V:ah38
/??nOVvt
+rOd0?
/* 6ieP` bct
**FileAccess.java b'G!)n
*//文件访问(定位，写) =' #yG(h
package NetFox; <z-+{-?z~
import java.io.*; E%\Ohs7
6zW3!_tz
k!sk\~>YO
public class FileAccessI implements Serializable{ t x#(K#/
wRj&k(?*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -{S:sK.o
RandomAccessFile oSavedFile; Y kcN-
long nPos; =BBDh`$R
8=j_~&*
|kkg1M#
public FileAccessI() throws IOException A$o?_
{ &13#/
this("",0); 1WLaJ%Fv
} :%"$8o*0W
psE&Rx3)
!"N-To-c
public FileAccessI(String sName,long nPos) throws IOException UWq[K&vQZ
{ T&kr IZw
oSavedFile = new RandomAccessFile(sName,"rw"); R]Pv=fn
this.nPos = nPos; M`.v/UQn
oSavedFile.seek(nPos); {~eVZVv
} ;bes#|^F
L2^M#G@t
i 9wk)
public synchronized int write(byte[] b,int nStart,int nLen) (Zv/(SE5%
{ w;KNS'
int n = -1; m}?(c)ST
try{ Y@[Dy
oSavedFile.write(b,nStart,nLen); hZLwg7X!
n = nLen; 5<L+T
} .wz.Jr`{
catch(IOException e) S(h+,+289
{ \>r<z46x
e.printStackTrace (); Kv-4VWh
} eh}{\P
2 1]87$
&\/p5RX
return n; UqsX@jL!
} [5TGCGxP{
\v[?4[
tJ!s/|u(
} NU$?BiB?R
8^6dK
^K n{L
/* xdd;!HK,
**SiteInfoBean.java XKepk? E
*/ u.L{3gkT
package NetFox; uO;_T/^u
T_*R^Ukb5
$oU40HA)W]
public class SiteInfoBean { {9*k \d/;
@`Foy
]-G10p}Ph-
private String sSiteURL; //Site's URL !L_\6;aP,x
private String sFilePath; //Saved File's Path [`Dv#
private String sFileName; //Saved File's Name .3yxg}E>{
private int nSplitter; //Count of Splited Downloading File kA%"-$3
CP!>V:w%9!
$d_%7xx
public SiteInfoBean() {P@OV1
{//nSplitter的缺省值为5 COk;z.Kn
//default value of nSplitter is 5 XhEd9>#
this("","","",5); ;;g'C*_
} j^'op|l
/K<.$B8
UuvI?D
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) LU4k/
{ }hd:avze
sSiteURL= sURL; `8rInfV
sFilePath = sPath; s j{i
sFileName = sName; rYYAZ(\8
this.nSplitter = nSpiltter; j[<}l&
U$5 lh
WGeTL`}dh
} _.y0QkwV
^q=D!g
_@Le MNv
public String getSSiteURL() {(,[
{ k9pOY]_Y
return sSiteURL; o:irwfArv
} ,3tcti~sZ
4#^?-6
\E3evU
public void setSSiteURL(String value) !9knFt43
{ <_~>YJ
sSiteURL = value; PtT=HvP!k
} W{!GL
\KJ\>2Y
D-<9kBZs
public String getSFilePath() 8Vb.%f&I
{ 1JI\e6]I
return sFilePath; v2uyn
} HX77XTy
]c'12 g]h
E1uyMh-dy
public void setSFilePath(String value) w[S!U<9/
{ 8~>5k
sFilePath = value; DL0i
} k[p7)ec
5 UQbd8
NY`$D}Bi
public String getSFileName() VaIFE~>E&
{ &>m# "A\^
return sFileName; <s7OY`(8
} wtY*{m2
D+ )R_
= UT^5cl(
public void setSFileName(String value) (ugB3o
{ C\B&'+uR
sFileName = value; LK1 r@
} VdZmrq;?/
vxRy7:G"
^6E+l#
public int getNSplitter() ?zD?-
{ {T0f]]}Q
return nSplitter; K9YD)351t
} '9Hah
[8o!X)
5D32d1A
public void setNSplitter(int nCount) Wp[R$/uT
{ .%(Q*ioDh
nSplitter = nCount; cCoa3U/
} ]H4T80wm&
} 0~5'O[NhF
< c}cgD4
v&NC` dVR
/* PsLMV:O9S
**Utility.java v;q<h
*/ 8Q%rBl.
package NetFox; J4-64t nZ
;;9W/m~]
xsPE UK&g
public class Utility { oP$l(k
J4Ix\r_
$cxulcay=
public Utility() ecoi4f
{ i+2fWi6Z+
MMZdF{5@G
sMq*X^z )?
} ;!JI$_-\
S-^RZ"
//线程睡眠 Ez*9*]O*+
public static void sleep(int nSecond) /WlpRf%
{ yH'vhtop
try{ *h`%u8/{
Thread.sleep(nSecond); X5|<qu
} @C]Q;>^|
catch(Exception e) *<PQp
{ $R'
e.printStackTrace (); cZ@z]LY.g
} Yy$GfjJtL]
} Vd-\_VP20
b#:Pl`n6u
//日志 }E\ b_.
public static void log(String sMsg) p@H3NX
{ vakAl;
System.err.println(sMsg); $\0%"S
} PfaBzi9?f
J;K-Pv+
JP2zom
public static void log(int sMsg) |6%B2I&c
{ 'Y ZYRFWXM
System.err.println(sMsg); FY^[?lj
} ],lrT0_cT
} SIBNU3;DL
6/m|Sg.m
(~R[K,G
/* s)=fs#%
**TestMethod.java (8(7:aE$
*/ Hl,.6>F?
package NetFox; kjo,?$r %
p97}HT}
jm_b3!J
public class TestMethod { wF +9Iu
tFY;q##z
>IL[eiiPG
public TestMethod() K8sgeX|
{ ///xx/weblogic60b2_win.exe gy Jx>i
try{ 5AvbKT
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); lG\6z"K
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); tSr.0'CE
SiteFileFetch fileFetch = new SiteFileFetch(bean); }=1#ANM1
fileFetch.start(); a@E+/9
} vo9DmW
catch(Exception e){e.printStackTrace ();} %_rdO(
@l7~Zn
HA?<j|M
} Hh_Yd)
d-=RS]j;j
8n.sg({g
public static void main(String[] args) qUH02"z@9
{ YEL,TU
new TestMethod(); PdUlwT?8C
} :x36^{7
} p)5j~Nl
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