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)); j\o<r0I
} ^/H9`z;
for(int i=0;i<nEndPos.length-1;i++) :MIJfr>z
{ ?)#qBE ]
nEndPos = nStartPos[i+1]; 5,;>b^gXY`
} Z/p>>SCak
nEndPos[nEndPos.length-1] = nFileLength; !T<4em8
} U<aT%^_
} Rx}*I00
B]""%&! O
)fRZ}7k:
//启动子线程 xlW`4\ Pa
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; @5im*ubzM
for(int i=0;i<nStartPos.length;i++) .w .`1 g
{ S*5hO) C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \@3B%RW0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,y'E#_cTgQ
nStartPos,nEndPos,i); "G&S`8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |lnMT)^D
fileSplitterFetch.start(); zP F0M(
} >Fzs%]M
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), q3CcXYY
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ecZT|X4u
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", D (>,#F
nEndPos = " + nFileLength); m7|}PH"7
// fileSplitterFetch[nPos.length-1].start(); |v'_Co0ki
VN5UJ!$?J
p,)~w1|
//等待子线程结束 D;@nrj`.
//int count = 0; ^E)*i#."4
//是否结束while循环 %+=y!
boolean breakWhile = false; D>Ub)i
$P{|^ou3a#
19r4J(pV
while(!bStop) `~0^fSww
{ 3t*e|Ih&j5
write_nPos(); 1hz:AUH
Utility.sleep(500); &"h 9Awn2
breakWhile = true; ,k,RXgQ
e?V7<7$
TVVr<r
for(int i=0;i<nStartPos.length;i++) 0pC}+ +
{ 9}=]oX!+V
if(!fileSplitterFetch.bDownOver) ;F/yS2p
{ 5}pn5iI
breakWhile = false; ]I+"";oQGB
break; }u>F}mUa
} -_p+4tV
} h^)R}jy+f
if(breakWhile) YEbB3N
break; gq'}LcV
;VLv2J*
2NNAsr}L
//count++; 24}?GO
//if(count>4) p H5iv>H
// siteStop(); |3a1hCxt
} 1;U `e4"
I|`/#BYbW
&{x%"Aq/
System.err.println("文件下载结束！"); GW29Rj1
} 06Irx^n
catch(Exception e){e.printStackTrace ();} Zs(I]^w;d
} g}vOp3^
`2B,+ytW8
)}G?^rDH(
//获得文件长度 v4pFts$J
public long getFileSize() 0Bo7EV
{ ?tf/#5t}
int nFileLength = -1; ;j#(%U]Vp
try{ _0v+g1x
URL url = new URL(siteInfoBean.getSSiteURL()); |UGmIm%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :cvZk|b%
httpConnection.setRequestProperty("User-Agent","NetFox"); w6-A-M6hD
B5nzkJV<X
qG=>eRR
int responseCode=httpConnection.getResponseCode(); 9L"Z ~CUL
if(responseCode>=400) #)qn$&.H
{ *b$8O
processErrorCode(responseCode); P$a `8~w
return -2; //-2 represent access is error )t$<FP
} /YyimG7
_D{V(c<WD
XMR$I&;G8
String sHeader; w;=fi}<G|e
Nx%]dOa
FE0}V}\=h
for(int i=1;;i++) 7jj.maK
{ h6yXW!8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); &pL.hM^
//Utility.log(in.readLine()); :75$e%'A
sHeader=httpConnection.getHeaderFieldKey(i); cJ}J4?
if(sHeader!=null) -=tf)
{ o!\Q,
if(sHeader.equals("Content-Length")) ')bas#=uP
{ 'V*ixK8R0
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ="k9 y
break; xD:t$~
} TjUg8k
} )@IDmz>
else @y|ZXPC#
break; X\z`S##kj
} AM[#AZv
} 4;rt|X77
catch(IOException e){e.printStackTrace ();} JTw< 4]
catch(Exception e){e.printStackTrace ();} vM.Y/,7S
\1[=t+/
i42M.M6D$
Utility.log(nFileLength); @1`!}.Tk
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3?R56$-+
return nFileLength; z]^u@]@NC
} ,n}h_ct
~x!"(
d4 Hpe>
//保存下载信息（文件指针位置） Wk0"U V
private void write_nPos() p)dD{+"/2
{ 3@t&5UjwQ
try{ )&nfV5@"
output = new DataOutputStream(new FileOutputStream(tmpFile)); \!+#9sq0
output.writeInt(nStartPos.length); NSsLuM=.
for(int i=0;i<nStartPos.length;i++) UdIl5P
{ z'W8t|m}Pb
// output.writeLong(nPos); C1x"q9|\`
output.writeLong(fileSplitterFetch.nStartPos); mMz^I7$
output.writeLong(fileSplitterFetch.nEndPos); y7x&/2
} )1EF7.|
output.close(); $X>$)U'p&-
} 6t,_Xqg*
catch(IOException e){e.printStackTrace ();} w%3R[Kdzk
catch(Exception e){e.printStackTrace ();} ~6<'cun@x
} :EkhF6B/
hk +@ngh%
]c Or$O*
//读取保存的下载信息（文件指针位置） b3zxiq x
private void read_nPos() s`Y8&e.Yr
{ -msfiO
try{ \8KAK3i'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); + YjK#
int nCount = input.readInt(); ;cFlZGw
nStartPos = new long[nCount]; 2b[R^O}
nEndPos = new long[nCount]; z-J?x-<
for(int i=0;i<nStartPos.length;i++) 'l&),]|$)
{ &e-MOM2&
nStartPos = input.readLong(); #Yqj27&
nEndPos = input.readLong(); .# Jusd
} "B$r{ vG
input.close(); =vpXYj
} d'x'hp%
catch(IOException e){e.printStackTrace ();} "1-gMob
catch(Exception e){e.printStackTrace ();} (]Pr[xB
} vi4lmkyh^
fFSQLtm?E
Z [aKic
private void processErrorCode(int nErrorCode) pZ IDGy=~
{ 3YFbT Z
System.err.println("Error Code : " + nErrorCode); ^z _m<&r
} #},4m
kT=KxS{
1luRTI8^
//停止文件下载 }Qqi013E L
public void siteStop() &>YdX$8x
{ A~!v+W%vO1
bStop = true; .!B>pp(9
for(int i=0;i<nStartPos.length;i++) (FY<%.Pa
fileSplitterFetch.splitterStop(); M%vZcP
@[s+5_9nk
Yp;6.\Z8[
} k*U(ln
} ,drcJ
//负责部分文件的抓取 tn\PxT
**FileSplitterFetch.java KysJ3G.k\
*/ C<T)'^7z
package NetFox; w.:fl4V
=Qf.
RyN}Gz/YN
import java.io.*; FUD M]:XQ
import java.net.*; Y\e8oIYu7
Q!T+Jc9N
&|LP>'H;
public class FileSplitterFetch extends Thread { Mq#sSBE<K
z0v|%&IK
_[kZ:#
String sURL; //File URL x=7qC#+)
long nStartPos; //File Snippet Start Position Wpdn^=dhL
long nEndPos; //File Snippet End Position p bT sn
int nThreadID; //Thread's ID ?kF_C,k/>N
boolean bDownOver = false; //Downing is over #cF ?a5
boolean bStop = false; //Stop identical CkHifmc(u-
FileAccessI fileAccessI = null; //File Access interface X`+8rO[
^T.icSxP
8Q*477=I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Y~fa=R{W
{ ,t!K? Y
this.sURL = sURL; j@98UZ{g\
this.nStartPos = nStart; mZgYR~
this.nEndPos = nEnd; F s{}bQyQ
nThreadID = id; &3:U&}I
fileAccessI = new FileAccessI(sName,nStartPos);//定位 v?)u1-V0
} ;r1.Uz(
NmH:/xU?^
oE;SZ"$x
public void run() d$;1%rRj8
{ v<Ozr:lL
while(nStartPos < nEndPos && !bStop) |#Q4e51H
{ ~R$Ko(N
pAY[XN
o=}vK[0u
try{ yf/c
URL url = new URL(sURL); vr$zYdV>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); M#5*gWfq9
httpConnection.setRequestProperty("User-Agent","NetFox"); ?!{nNJ
String sProperty = "bytes="+nStartPos+"-"; w%NT 0J
httpConnection.setRequestProperty("RANGE",sProperty); Ia'm9Z*
Utility.log(sProperty); 0\X'a}8Bu
>(9"D8
N+V_[qr#
InputStream input = httpConnection.getInputStream(); X *fle
//logResponseHead(httpConnection); L*'3f~@Q
8YLS/dN0 w
/5s,< 0Kz
byte[] b = new byte[1024]; 7XDze(O5
int nRead; ZQ_&HmgRy
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) vrr`^UB2
{ @8$3Q,fF(
nStartPos += fileAccessI.write(b,0,nRead); q]}1/JZS
//if(nThreadID == 1) ;V:Cf/@@R
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); h]w5N2$}?
} qbunP!
-gzY~a
jwW6m@+
Utility.log("Thread " + nThreadID + " is over!"); L>PPAI
bDownOver = true; %(v<aEQtt
//nPos = fileAccessI.write (b,0,nRead); @9}SHS
} !vQDPLBL
catch(Exception e){e.printStackTrace ();} n#fc=L1U
} &58TX[#
} )`V__^
t%'0uB#v1
}2;{}J
//打印回应的头信息 D_(K{?KU
public void logResponseHead(HttpURLConnection con) bpv?$j-j
{ km[PbC
for(int i=1;;i++) q*36/I
{ <M,A:u\qSQ
String header=con.getHeaderFieldKey(i); 3L5o8?[
if(header!=null) Ze:Y"49S+>
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'aAay*1
Utility.log(header+" : "+con.getHeaderField(header)); rf:CB&u
else Jemb0Qv
break; Z^?YTykH
} ~p'DPg4
} S^/:O.X)c,
Z9+xB"q2
h=`1sfz
public void splitterStop() UZqQ|3
{ : ~R:[T2P
bStop = true; y9@DlK
} =w/S{yC
8g!C'5
]B'H(o R<|
} yS2[V,vS7
,2y" \_
p#T^o]+
/* "v9i;Ba>+
**FileAccess.java YJ[Jo3M@j0
*//文件访问(定位，写) c~=yD:$
package NetFox; 0s%rd>3
import java.io.*; }F;Nh7?
KDmzKOl
SyWLPh
public class FileAccessI implements Serializable{ R/UL4R,)^
-1P*4H2a
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^1 P@BRh
RandomAccessFile oSavedFile; n!>#o1Qr
long nPos; ?4&C)[^
1MF0HiC
g12mSbf=9
public FileAccessI() throws IOException hV6=-QL*B
{ u3XQ<N{Gj
this("",0); faJ>,^V#
} x(UOt;
J91O$szA
M^$liS.D
public FileAccessI(String sName,long nPos) throws IOException w' gKE'c
{ ~l=Jx*
oSavedFile = new RandomAccessFile(sName,"rw"); |##rs
this.nPos = nPos; _?IP}}jA:
oSavedFile.seek(nPos); )ZP-t!).G#
} >aaHN1Ca
_H(:$=$Q
@jp}WwC/
public synchronized int write(byte[] b,int nStart,int nLen) eK]$8l|LI
{ IUJRP
int n = -1; fsxZQ=-PW
try{ bR*/d-v^
oSavedFile.write(b,nStart,nLen); jRv j:H9
n = nLen; nYv`{0S+m
} Oy `2ccQ#
catch(IOException e) (fYrb#]!y
{ a=!I(50
e.printStackTrace (); n~wNee
} t'F_1P^*/
Wxxnc#;lv
?[ts<Ltp
return n; 1~x=bphS
} JnT1-=t.
52L* :|b
(6WSQqp
} S/XkxGZ2
Gw;[maM!%`
Q6r!=yOEY
/* OGjeE4
**SiteInfoBean.java )ZI9n7
*/ r,`59
package NetFox; @Q=P6Rz {S
L< gp "e
.LX8ko
public class SiteInfoBean { 8O)!{gB
]q2g[D o5
l*yh(3~}
private String sSiteURL; //Site's URL H3?HQ>&O7
private String sFilePath; //Saved File's Path EK:s#
private String sFileName; //Saved File's Name qC%[J:RwF
private int nSplitter; //Count of Splited Downloading File t[.wx.y&0
;goR0PN
N!`8-ap\^
public SiteInfoBean() qhPvU( ,
{//nSplitter的缺省值为5 V@(7K0
//default value of nSplitter is 5 ARZ5r48)
this("","","",5); $|2@of.
} "?lm`3W"
@"`{gdB$
2`o}neF{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) J01Y%W
{ #e!4njdM
sSiteURL= sURL; ;I#S m;
sFilePath = sPath; x 7;Zwd
sFileName = sName; y,*>+xk,
this.nSplitter = nSpiltter; _uR-Z_z
W:8*Z8?7
{\?zqIM
} #()u=)
4+V+SD
%>cl0W3x
public String getSSiteURL() B~/LAD_
{ _V9 O,"DDc
return sSiteURL; Cyb-}l
} H8ws6}C
CXQPbt[5
9 pGND]tIi
public void setSSiteURL(String value) 2ja@NT
{ jQKlJi2xu
sSiteURL = value; M#sDPT
} Y{ho[%
bHr2LhQCN
\qrSJ=}t
public String getSFilePath() R7L:U+*V"
{ btfjmR<Tp
return sFilePath; 8"M*,?.]
} K$H>/*&'~
`FP)-^A8
Dm=Em-ST6
public void setSFilePath(String value) G n_AXN
{ da[u@eNrnX
sFilePath = value; uh~/ybR
} q>~\w1%}a\
<&?gpRK
Y}bJN%M
public String getSFileName() `>1"v9eF
{ idC4yH42
return sFileName; PC| U]
} 0`KB|=>
M1MpR+7S
5pBQ~m3
public void setSFileName(String value) ::y+|V/
{ ]y'/7U+
sFileName = value; (O N \-*
} ,_ XDCu @
UXXN\D
yn0OPjH
public int getNSplitter() eB:OvOol*^
{ >A$J5B>d
return nSplitter; W |]24
} !OJ@ =y`i
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public void setNSplitter(int nCount) K)Nbl^6x
{ N#;k;Z'iL
nSplitter = nCount; r@&d88U:
} y@;4F n/
} oh '\,zpL
LF'M!C9|
yJaQcGxE"
/* JD^&d~n_
**Utility.java :<OInKE>Cx
*/ ?"p:6%GFz
package NetFox; =?`5n|A*
}}3*tn<6
SWjOJjn
public class Utility { Ge+&C RhyX
ZDZPJp,
u"K-mr#$[o
public Utility() ~RVx~hh
{ J?XEF@?'G
um@RaU
`0rEV_$
} A#W%ud4
71+J{XOC
//线程睡眠 K?_4|
public static void sleep(int nSecond) TxhTK5#f
{ ,w|f*L$
try{ uc?QS~H&w
Thread.sleep(nSecond); zh$[UdY6
} q/,W'lQ\;
catch(Exception e) MOJ-q3H^W
{ 6&=xu|M<x=
e.printStackTrace (); "HW~|M7>(
} pa&*n=&cL
} Aa;R_Jz
D-.XSIEMu
//日志 4WnB{9 i`I
public static void log(String sMsg) YF=@nR$_~j
{ k/vE|
System.err.println(sMsg); ?op6_a-wm
} hq.z:D
cLH|;
Bv$;yR
public static void log(int sMsg) t;9f7~
{ [R j=k)aBm
System.err.println(sMsg); <CL0@?*i9
} D"F5-s7
} jxL5L[
byM/LE7)
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/* s> JmLtT
**TestMethod.java VdR5ZP
*/ wO!k|7:Z
package NetFox; AigL:4[
$|!VP'VI
{A4"KX(U
public class TestMethod { A%n l@`s,
M_V\mYC8I
M'D;2qo
public TestMethod() c"%XE#D
{ ///xx/weblogic60b2_win.exe 2.Ym
try{ w .l2
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6hSj)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); F;jl0)fBR=
SiteFileFetch fileFetch = new SiteFileFetch(bean); $kJvPwRO
fileFetch.start(); GLA,,i'i9
} !3K6ew>Sf
catch(Exception e){e.printStackTrace ();} +nRO<
mq~7v1kw
u>H^bCXI
} De[!^/f;T
,,oiL
Vw=eC"
public static void main(String[] args) =^4 vz=2
{ )'M<q,@<(
new TestMethod(); mFOuE5
} <tAn2e!
} _s!(9
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