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)); LMTz/M
} uwo\FI
for(int i=0;i<nEndPos.length-1;i++) d_aHUmI^"
{ $s"{C"4q
nEndPos = nStartPos[i+1]; } za"rU
} c=#V*<
nEndPos[nEndPos.length-1] = nFileLength; :oO ?A
} "1|\V.>>;
} O"V;otlC
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1yV+~)by3
//启动子线程 pUD(5v*0R
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; f S-PM3
for(int i=0;i<nStartPos.length;i++) iM(Q-%HP_
{ r%412#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), t5;)<N`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gUHx(Fi[4
nStartPos,nEndPos,i); dBNx2T}_0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U2vM|7]VP
fileSplitterFetch.start(); ,Aw Z%
} RAB'%CY4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), p4^&G/'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); `Y_G*b.Rm
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 8Ai\T_l
nEndPos = " + nFileLength); 7-A/2/G<
// fileSplitterFetch[nPos.length-1].start(); nR`)kORc
>vKOG@I
v$~$_K
//等待子线程结束 eI3ZV^_Ps
//int count = 0; SI, t:=D
//是否结束while循环 vtF|:*h
boolean breakWhile = false; EaKbG>
><i: P*ht
E_-QGE/1
while(!bStop) FW)VyVFmk
{ OAo;vC:^
write_nPos(); ;DXg
Utility.sleep(500); e6gLYhf&
breakWhile = true; OWT|F0.1$k
P"%f8C~r
Yaj}_M-
for(int i=0;i<nStartPos.length;i++) =:BTv[lv
{ Z]08gH
if(!fileSplitterFetch.bDownOver) PnZC I!Mw
{ 1\ Gxk&
breakWhile = false; \[&&4CN{
break; ,)M/mG?,
} _"[Ls?tRX
} 6KDm#7J
if(breakWhile) G.3yuok9
break; #\Zr$?t|V
eI,H
2{<o1x,Ym
//count++; \![ p-mW{
//if(count>4) Q?>DbT6
// siteStop(); 7#(0GZN9h%
} se=;vp]3a
Xm3r)Bm'3
(7Ln~J*
System.err.println("文件下载结束！"); pGd@%/]AO
} Zm*qV!
catch(Exception e){e.printStackTrace ();} ,ygUy]
} 89Ir}bCr
:!ablO~
WG*),P?
//获得文件长度 A DVUx}
public long getFileSize() ZvwU
{ *vzEfmN:d
int nFileLength = -1; }0,dG4Oo=
try{ N}>[To3
URL url = new URL(siteInfoBean.getSSiteURL()); 2Q5-.2]
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AQwai>eL
httpConnection.setRequestProperty("User-Agent","NetFox"); |k^C-
055C1RV%
$plqk^P
int responseCode=httpConnection.getResponseCode(); [}!0PN?z~A
if(responseCode>=400) 6aLRnH"Ud
{ ^?NLA&v<
processErrorCode(responseCode); AuT:snCzR
return -2; //-2 represent access is error %{-r'Yi%
} 2"HG6"Rr
5W0s9yD
0n}v"61q
String sHeader; (67byO{
u\;d^A
ZUkM8M$c
for(int i=1;;i++) C_Z/7x*>d
{ 0O[le*3b
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); YSrjg|k*
//Utility.log(in.readLine()); &\%\"Zh
sHeader=httpConnection.getHeaderFieldKey(i); ""A6n{4
if(sHeader!=null) [bw1!X3
{ O?ODfO+>
if(sHeader.equals("Content-Length")) g(9kc<`3'D
{ j WSgO(y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }Ogb|8
break; bh(}f.@ 9
} ?)T@qn+
} @]!9;?so
else 6_:I~TTX
break; D|*yeS4>
} K|Eelhm
} D5!#c-Y-
catch(IOException e){e.printStackTrace ();} 1_};!5$.
catch(Exception e){e.printStackTrace ();} 1tLEKSo+
#0PZa$kM(o
n =WH=:&
Utility.log(nFileLength); 2Z5_@Y
)|_L?q#w!'
a?yU;IKJ
return nFileLength; {1qr6P,"
} 1[J|AkN
F2Y!aR
pKno~jja
//保存下载信息（文件指针位置） r@/@b{=
private void write_nPos() Q :.i[
{ _a f $0!
try{ cUr!U\X[
output = new DataOutputStream(new FileOutputStream(tmpFile)); na|sKE;{
output.writeInt(nStartPos.length); \KzH5?
for(int i=0;i<nStartPos.length;i++) @v#,SF{
{ g/_0WW]}
// output.writeLong(nPos); )E}@h%d
output.writeLong(fileSplitterFetch.nStartPos); k>\v]&|T`
output.writeLong(fileSplitterFetch.nEndPos); 2W2T
} ?T.=ym
output.close(); I$MlIz$l v
} yM7Iq)o6u
catch(IOException e){e.printStackTrace ();} /!MVpi'6&
catch(Exception e){e.printStackTrace ();} ``eam8Az_U
} jijwHL
:Nv7Wt!
6ypLE@Mk
//读取保存的下载信息（文件指针位置） vQ]d?Tp
private void read_nPos() wZN_YFwQ
{ TEh.?
try{ G|[{\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]Vmo>
int nCount = input.readInt(); gO)":!_n W
nStartPos = new long[nCount]; )$1>6C\
nEndPos = new long[nCount]; T2/:C7zL
for(int i=0;i<nStartPos.length;i++) !n`|k
{ gb|;]mk*"
nStartPos = input.readLong(); IxS%V31
nEndPos = input.readLong(); iPCCTs
} ,wM4X']HR
input.close(); &x[7?Y L
} 0#DEh|?
catch(IOException e){e.printStackTrace ();} nJGs,~"
catch(Exception e){e.printStackTrace ();} X9NP,6
} e0h[(3bXs$
+'-.c"
vg5_@7
private void processErrorCode(int nErrorCode) /s~S\dG
{ EEnl'
System.err.println("Error Code : " + nErrorCode); /aMOZ=,q}
} aWlIq(dU
hxK;f
\xbUr`WBY
//停止文件下载 \hZ%NLj
public void siteStop() ZZ!">AN`^
{ KbtV>
bStop = true; dzBP<Xyh
for(int i=0;i<nStartPos.length;i++) &b`W<PAc?4
fileSplitterFetch.splitterStop(); D4,>g )B
#CaPj:>[
PkI+z_
} v&'#Gg
} (S?Y3l|
//负责部分文件的抓取 5QLK
**FileSplitterFetch.java as!a!1
*/ ~r!(V;k{
package NetFox; *<!q@r<d
&H]/'i-
RG""/x;
import java.io.*; *;]}`r
import java.net.*; }ePl&-9T
*=2W:,$
~bxev/$d
public class FileSplitterFetch extends Thread { 4|E^ #C
j7gw?,
xsn=Ji2 F
String sURL; //File URL )?UoF&c/
long nStartPos; //File Snippet Start Position Uu5(/vw]
long nEndPos; //File Snippet End Position eF22 ~P
int nThreadID; //Thread's ID cl2_"O
boolean bDownOver = false; //Downing is over #}FUau$
boolean bStop = false; //Stop identical V(F9=r<X
FileAccessI fileAccessI = null; //File Access interface _OTVQo Ap
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException M|K^u.4
{ h7!O K
this.sURL = sURL; %z-*C'j5H
this.nStartPos = nStart; HyU:BW;
this.nEndPos = nEnd; rO$pj~!|Q
nThreadID = id; ?nGiif
fileAccessI = new FileAccessI(sName,nStartPos);//定位 MCmb/.&wu
} xdm\[s
{]<c6*gQ
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public void run() T5."3i
{ 1.F&gP)9
while(nStartPos < nEndPos && !bStop) LK~aLa5wG
{ 8ROKfPj;z
p8_^6wfg
]*\MIz{56'
try{ hj9TiH/+
URL url = new URL(sURL); Td|u@l4B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); GQn:lu3j:
httpConnection.setRequestProperty("User-Agent","NetFox"); oNyYx6q:Q
String sProperty = "bytes="+nStartPos+"-"; WC`h+SC`.
httpConnection.setRequestProperty("RANGE",sProperty); ?gl&q+mv
Utility.log(sProperty); G/<zd)
#BUq;5
7TMq#Pb
InputStream input = httpConnection.getInputStream(); gCb+hQq\
//logResponseHead(httpConnection); 2URGd#{VQ
&Mk!qE<:N
]=qauf>3
byte[] b = new byte[1024]; oCaYmi=:
int nRead; &sWr)>vs
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) p8~lGuH
{ !%,7*F(
nStartPos += fileAccessI.write(b,0,nRead); jU j\<aW
//if(nThreadID == 1) P3&s<mh
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ORs:S$Nt$
} A_zCSRF,
BB/wL_=:
i D IY|
Utility.log("Thread " + nThreadID + " is over!"); I?3b}#&V9
bDownOver = true; KFd +7C9
//nPos = fileAccessI.write (b,0,nRead); 7Ed0BJTa
} 112WryS
catch(Exception e){e.printStackTrace ();} qjP~F
} W^tD6H;
} '" "v7
A-CU%G9
S} m=|3%y
//打印回应的头信息 $72eHdy/yl
public void logResponseHead(HttpURLConnection con) DQQ]grU
{ 6DHK&<=D8
for(int i=1;;i++) SN}K=)KF#
{ DWt|lO
String header=con.getHeaderFieldKey(i); K6IT$$g
if(header!=null) .[O{,r
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;`78h?`
Utility.log(header+" : "+con.getHeaderField(header)); 2!sPgIz
else E(r_mF7:
break; V#7,vas
} ,=u;1
} NZvgkci_(u
yxt"vm;
]<>cjk.ya
public void splitterStop() =6[.||9
{ u?Ffqt9'
bStop = true; ?s^qWA
} ?}cmES kX@
"[_j8,t`
.`OU\LA
} dw"Es;^
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t{]Ew4Y4%O
/* U6M~N0)Yr
**FileAccess.java VhUWws3E
*//文件访问(定位，写) m^3x%ENZ
package NetFox; \)~d,M}kK
import java.io.*; el9P@r0
gZ,h95'
bw P=f.
public class FileAccessI implements Serializable{ 6Rn?pe^
4E^ ?}_$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 H0afu)$,
RandomAccessFile oSavedFile; ~XTC:6ts
long nPos; ~S8:xG+s
N#T'}>ty
^jMrM.GY
public FileAccessI() throws IOException + `|A/w
{ s:3[#&PQpN
this("",0); o9eOp3w30
} [I *_0
oP`l)`
GTP'js
public FileAccessI(String sName,long nPos) throws IOException 6'Q{xJe?
{ {rKC4:
oSavedFile = new RandomAccessFile(sName,"rw"); h3?>jE=H
this.nPos = nPos; fN&\8SPE
oSavedFile.seek(nPos); dR S:S_
} |4df)
xb,d,(^]R
)^ah, ;(
public synchronized int write(byte[] b,int nStart,int nLen) [CJ<$R !
{ 1+FVM\<&
int n = -1; q?}C`5%D
try{ k[r^@|
oSavedFile.write(b,nStart,nLen); vE:*{G;Y
n = nLen; keAoJeG,J
} su%(!XJQpg
catch(IOException e) Z2g'&,uc#
{ |.N[NY
e.printStackTrace (); d_!Z /M,
} 3`^@ymY
Y9)j1~
o$No@~%v
return n; 1h$?,
} ;'7(gAE
V`I4"}M1
7}kJp%-
} ! ?g+'OM
ix!xLm9\
m/=nz.
/* ~>CvZ7K
**SiteInfoBean.java G}nJ3
*/ lFzVd N
package NetFox; #t ;`
]fM|cN8(zM
;{ifLI0#
public class SiteInfoBean { s)1-xA{'.
=)Xj[NNRT
g:Hj1!'
private String sSiteURL; //Site's URL ~:DL{ZeEb
private String sFilePath; //Saved File's Path xKUL}>8
private String sFileName; //Saved File's Name yvd)pH<a2
private int nSplitter; //Count of Splited Downloading File 5BVvT `<
[^qT?se{
981-[ga`Y
public SiteInfoBean() -<#) ]um
{//nSplitter的缺省值为5 NM3;l}Y8
//default value of nSplitter is 5 nTy]sPn
this("","","",5); 4aXIRu%#7
} 1/}H 0\9'
=-U0r$sK+F
sO.MUj;
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) gm9*z.S\'
{ 0kE[=#'.'
sSiteURL= sURL; =QqH`.3
sFilePath = sPath; &A0OYV3i.
sFileName = sName; CHgip&(.F
this.nSplitter = nSpiltter; U{2xgNJ
i~';1 .g
f'*-<sSr
} 'PF>#X''
5u!\c(TJ+
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public String getSSiteURL() Pq /5Dy
{ (0 T!-hsP
return sSiteURL; \L Q+ n+
} _C !i(z!d
J"r?F0
*&_*G~>D
public void setSSiteURL(String value) :33@y%>L
{ @Xo*TJB
sSiteURL = value; PT/Nz+
} *ID=X!v
94tfR$W;-
kdNo<x1o
public String getSFilePath() FGV L[\
{ T[\1=h]
return sFilePath; HI8mNX3 "j
} '`jGr+K,wU
:v^/k]S
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public void setSFilePath(String value) > 80{n8
{ /!5Wd(:
sFilePath = value; ] ?DU8
} m{q'RAw
tguB@,O
*'Yy@T8M
public String getSFileName() R"t#dG]1t
{ _b&|0j:Ud
return sFileName; ~,)jZ-fw
} 6W i n!4
d/d)MoaJ*t
hP6f
public void setSFileName(String value) B;9,Qbb
{ NUsxMhP
sFileName = value; ;.}L#'0j
} +x%u?ZR
&_L@hsm
Ju+3}
public int getNSplitter() |*bUcS<S
{ tq L(H25z
return nSplitter; "to!&@I| 4
} #T7v]@K67
3ahriZe
R$&;
public void setNSplitter(int nCount) 5Kzt8Tv[
{ {ZeY:\G~
nSplitter = nCount; zx#Gm=H4
} {5dVK
} 't<iB&wgF
j)J |'b|
A]BeI
/* ]Uv,}W
**Utility.java kvbZx{s
*/ !JCs'?A
package NetFox; 7By7F:[b
?|M-0{
v-8>@s jy8
public class Utility { 2C S9v
un "I
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public Utility() H{}&|;0
{ E*'YxI
Zmu
XCM!8x?K
} Jm4uj&}3
Y'/6T]a
//线程睡眠 \[G'cE
public static void sleep(int nSecond) ifn=De3+
{ zhJeTctRz
try{ pBqf+}g4
Thread.sleep(nSecond); s<k[<
} 1Yb&E7j
catch(Exception e) NpVL;6?7T
{ ZKi&f,:
e.printStackTrace (); 'w:ugb9]
} lelmX
} T}Tv}~!f
i c{I
//日志 :w8{BIUN)
public static void log(String sMsg) S m(*<H
{ m H:Un{,
System.err.println(sMsg); T!jh`;D+
} J jAxNviG
WuK<?1meN
V!:!c]8F
public static void log(int sMsg) e:G~P u`
{ >.wZEQ6QK
System.err.println(sMsg); $yOB-
} t24`*'
} Qa2h#0j
}IygU 6{G
Dw i-iA_q
/* 'aNkU
**TestMethod.java Pt"K+]Ym
*/ *f+s
package NetFox; ^wy
eU"yF >6'
?+}Su'pv}
public class TestMethod { 9a_P 9s3w
Yc#Uu8f-
9B~&d(Bm
public TestMethod() \S h/<z
{ ///xx/weblogic60b2_win.exe Tg)F.):
try{ aImzK/
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); )"TVR{I%B
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); G2`YZ\
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8~U ^G[!
fileFetch.start(); ?0~g1"Y-*K
} ykQb;ZP8jh
catch(Exception e){e.printStackTrace ();} ~<k>07
L@Rgiq|v-|
+s#%\:Y M
} P(PBOB97
x(c+~4:_M
{t;o^pUF
public static void main(String[] args) `n>/MY
{ cyNE}
new TestMethod(); Y1cL dQn
} $#V'm{Hh
} jI,[(Z>
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