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)); ah"2^x
} UQPd@IVu6
for(int i=0;i<nEndPos.length-1;i++) aPcO9
{ $$A{|4,aI
nEndPos = nStartPos[i+1]; y`mEsj
} *.Y!ZaK
nEndPos[nEndPos.length-1] = nFileLength; @xtcjB9
} L G,XhN
} =Q.2:*d.
gEO#-tMjOQ
l#~Sh3@L(
//启动子线程 {u9(qd;;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fF_1ZKx+#!
for(int i=0;i<nStartPos.length;i++) kkyn>Wxv
{ V*5:Vt7N
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RT)0I;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lh7{2WQ
nStartPos,nEndPos,i); {h&*H[Z z
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); yIXM}i:
fileSplitterFetch.start(); ^(N+s?
} "0`r]5 5d
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), k1$|vzMh
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); <Sm=,Sw
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", k:m~'r8z
nEndPos = " + nFileLength); f3y_&I+zl
// fileSplitterFetch[nPos.length-1].start(); I?4J69'
V F6OC4 K
7T_g?!sdMh
//等待子线程结束 $Fc*^8$ryC
//int count = 0; 42Gr0+Mb
//是否结束while循环 qoB
boolean breakWhile = false; O*H:CW
MZ=U} &F
}UXj|SY
while(!bStop) x@v,qF$K
{ WB6g i2
write_nPos(); KT{<iz_
Utility.sleep(500); RNRMw;cT
breakWhile = true; &KbtW_
M[Y|$I}
9w11kut-!
for(int i=0;i<nStartPos.length;i++) *ErTDy(
{ fS1N(RZ1
if(!fileSplitterFetch.bDownOver) y"cK@sOo
{ `Wn0v2@a(~
breakWhile = false; Ea!}r|~]0
break; #8;^ys1f
} tI*u"%#t
} [53@'@26
if(breakWhile) +]I;C
break; ujmW {()
^zsCF0
`r_qvrC
//count++; iBN,YPo~
//if(count>4) 9^v|~f
// siteStop(); lH:TE=|4
} Z:O24{ro5
BB--UM{7
%lv2;-
System.err.println("文件下载结束！"); JF: QQ\
} cp0>Euco=
catch(Exception e){e.printStackTrace ();} ~M(K{6R
} [xO^\oQa=c
`q7I;w+g
9@QP?=\Y
//获得文件长度 ;NLL?6~
public long getFileSize() L9fhe,en
{ <g>_#fz"K
int nFileLength = -1; 2?QIK3"v
try{ #Sb1oLC
URL url = new URL(siteInfoBean.getSSiteURL()); *3S,XMS{O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (G#)[0<fX
httpConnection.setRequestProperty("User-Agent","NetFox"); lk6mu
<~"qz*_
p'KU!I}
int responseCode=httpConnection.getResponseCode(); <%>Q$b5
if(responseCode>=400) 9m!4U2N,s
{ Y&Pi`E9=
processErrorCode(responseCode); u\Fq\_
return -2; //-2 represent access is error _m3PAD4
} OjJlGElw
(mt,:hX
[g=yuVXNZZ
String sHeader; fU>"d>6!S
$o/?R]h
Z=825[p
for(int i=1;;i++) ;]Y.2 J
{ ZS>}NN
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); m[ay
//Utility.log(in.readLine()); K`(STvtM
sHeader=httpConnection.getHeaderFieldKey(i); d!G%n *
if(sHeader!=null) NjYpNd?g
{ eW\7X%I
if(sHeader.equals("Content-Length")) ll[U-v{
{ KDRIy@[e
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); VH#]67
break; rm2{PV<+d
} OPwp(b
} lsJ'dS
else tz1iabZ{
break; .Ks&r
} \w^U<_zq
} qa`bR%eH
catch(IOException e){e.printStackTrace ();} oIoJBn
catch(Exception e){e.printStackTrace ();} Iimz
f*W<N06EZ
l:j9lBS
Utility.log(nFileLength); [ {lF1+];@
{s=QwZdR
d?b2jZ$r]
return nFileLength; )l[ +7
} UbY-)9==
JY9Hqf
q/70fR7{v
//保存下载信息（文件指针位置） j#-ZL-N
private void write_nPos() -a&wOn-W
{ <gf:QX!
try{ ?v8RY,Q30
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~}83\LI}
output.writeInt(nStartPos.length); 9zi/z_G
for(int i=0;i<nStartPos.length;i++) r'{pTgm#
{ kRSu6r9
// output.writeLong(nPos); 'PV,c|f>
output.writeLong(fileSplitterFetch.nStartPos); JS({au
output.writeLong(fileSplitterFetch.nEndPos); P0' ;65
} KkJcHU
output.close(); v SHb\V#
} &Vnet7LfU
catch(IOException e){e.printStackTrace ();} Qs#v/r
catch(Exception e){e.printStackTrace ();} ^a<=@0|
} WAqR70{KM
isWB)$q
'e;*V$+
//读取保存的下载信息（文件指针位置） [A*vl9=
private void read_nPos() 7lR(6ka&/
{ P1Re7/
try{ 47`{ e_YP0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); t!D=oBCro
int nCount = input.readInt(); fm&l0
nStartPos = new long[nCount]; !G`w@E9M)
nEndPos = new long[nCount]; 2ZIf@C{P.
for(int i=0;i<nStartPos.length;i++) .Zf#L'Rf
{ 8Nci1o
nStartPos = input.readLong(); ` mALx! `
nEndPos = input.readLong(); w V27
} 6tzZ j:yq
input.close(); Ujq)h:`
} FE/&<g0,:
catch(IOException e){e.printStackTrace ();} ;S,g&%N
catch(Exception e){e.printStackTrace ();} W%0-SR
} '~liDz*O
\ {"8(ELX
kJJQcjAP:
private void processErrorCode(int nErrorCode) W=I%3F_C"R
{ oUltr
System.err.println("Error Code : " + nErrorCode); :T%,.sH
} n9cWvy&f
-}4H'%Z(i
$dorE~T
//停止文件下载 +-qD!(&-6
public void siteStop() '~3(s?B
{ N|1J@"H
bStop = true; 78qf
for(int i=0;i<nStartPos.length;i++) LP=!u~?
fileSplitterFetch.splitterStop(); =E4nNL?
3,N7Nfe
OK3B6T5w=
} wT*`Od8w
} K# _plpr
//负责部分文件的抓取 z_A%>E4
**FileSplitterFetch.java WYEvW<Hv
*/ 3i35F.=X,
package NetFox; ^]E| >~\
,A[HYc|uy
]vKxgfF
import java.io.*; .u W_(Rqg
import java.net.*; gj6"U{D
yMX4 f
%4n=qK9T5
public class FileSplitterFetch extends Thread { ZPZ1 7-
[r^f5;Z
#?}Y~Oe
String sURL; //File URL Y$oBsg\v
long nStartPos; //File Snippet Start Position 8ne5 B4
long nEndPos; //File Snippet End Position 6\~m{@
int nThreadID; //Thread's ID oY+RG|j@
boolean bDownOver = false; //Downing is over A{&Etu(K
boolean bStop = false; //Stop identical b*P\a
FileAccessI fileAccessI = null; //File Access interface \f /<#'
6"&&s
d{ OY
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Z;WqKIM#
{ nqiy)ZN#R
this.sURL = sURL; Y*w<~m
this.nStartPos = nStart; -pg7>vOq
this.nEndPos = nEnd; P3lNns3
nThreadID = id; 4fP>;9[F
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r10)1`[
} mN@0lfk;
Z(xn-
V :d/;~
public void run() hDmVv;M:
{ &,NHk9.aq
while(nStartPos < nEndPos && !bStop) YdC:P# Nf
{ J0o U5d=3
_ogT(uYyr
60X B
try{ ^+,mxV'8!
URL url = new URL(sURL); #i)h0ML/e
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); :,GsbNKW
httpConnection.setRequestProperty("User-Agent","NetFox"); nM R_ ?g
String sProperty = "bytes="+nStartPos+"-"; !aLByMA
httpConnection.setRequestProperty("RANGE",sProperty); \ZCc~muR
Utility.log(sProperty); $t}L|"=8X
ap;*qiNFQ
i$%;z~#wW
InputStream input = httpConnection.getInputStream(); 7J$ ^R6rh
//logResponseHead(httpConnection); pjbKMx
_|*3uGo:
U$0#j
byte[] b = new byte[1024]; __3Cjo^6&
int nRead; @["Vzg!I6"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Z)6bqU<LQE
{ D}b+#G(m[
nStartPos += fileAccessI.write(b,0,nRead); {/#?n["
//if(nThreadID == 1) atl0#FBd
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &yVii^
} ;'=!Fv
K})j5CJ/
{yspNyOx
Utility.log("Thread " + nThreadID + " is over!"); /\#qz.c2K
bDownOver = true; N;Hf7K
//nPos = fileAccessI.write (b,0,nRead); %v}:#_va]
} .HGEddcC
catch(Exception e){e.printStackTrace ();} hQ<"
} w9.r`_-
} Zu~ #d)l3N
puMpUY
';b/D
//打印回应的头信息 (qB$I\
public void logResponseHead(HttpURLConnection con) QdDdrR^&
{ 8iX?4qj{P
for(int i=1;;i++) N15{7,
{ 1s!hl{n<~
String header=con.getHeaderFieldKey(i); C(W?)6?
if(header!=null) IybMO5Mwn
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yKfRwO[j
Utility.log(header+" : "+con.getHeaderField(header)); ;=UrIA@y;=
else W P.6ea7k
break; 4(B,aU>y
} 2psI\7UjA]
} m$[\(Z(/
Fnll&TF
|q5\1}@:
public void splitterStop() ??1V__w
{ TS=p8@w}
bStop = true; 6Y}#vZ
} 2psLX
,F:l?dfB\I
oVmGZhkA@'
} |y;+xEl6
"d.qmM
! daXF&q
/* NGS/lKz
**FileAccess.java %)q5hB
*//文件访问(定位，写) b/O~f8t
package NetFox; ;Iv)J|*
import java.io.*; 7i6-Hq
UyK|KL
/=Q7RJ@P
public class FileAccessI implements Serializable{ k[G?22t
m_(+-G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 WW==
RandomAccessFile oSavedFile; =xa`)#4(
long nPos; \[Rh\v&
cB?HMLbG>
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public FileAccessI() throws IOException Dc BTW+
{ PiAA,
this("",0); Ij{{Z;o3
} WERK JA
rxm!'.+
vco:6Ab$
public FileAccessI(String sName,long nPos) throws IOException )v ['p
{ uCUQxFp
oSavedFile = new RandomAccessFile(sName,"rw"); ?~u"w OH'
this.nPos = nPos; MdEZ839J
oSavedFile.seek(nPos); Xg.\B1d
} r7w&p.?
>Qt#6X|
mC J/gWDY
public synchronized int write(byte[] b,int nStart,int nLen) =_Qt&B)
{ WR~uy|mX
int n = -1; G%rK{h
try{ =%$ _)=}J
oSavedFile.write(b,nStart,nLen); 52-^HV
n = nLen; W%~ S~wx
} VA2%2g2n{
catch(IOException e) xE4T\%-K
{ g-')|0py
e.printStackTrace (); =_L"x~0I-
} 1Qf5H!5vx
Mgf80r=
&)\0mpLK9
return n; JJ7-$h'0q
} QD /| zi
MLa]s* ; d
eFZ`0V0
} !|Vjv}UO
u%h]k ,(E
|h6)p;`gc
/* fN t
**SiteInfoBean.java rmWG9&coW
*/ B8[H><)o\y
package NetFox; jC;XY!d6
^$rt|]
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public class SiteInfoBean { d![EnkyL;
@@!t$dD
)"j_NlO
private String sSiteURL; //Site's URL TKj9s'/
private String sFilePath; //Saved File's Path % J+'7'g
private String sFileName; //Saved File's Name ^R K[-tVV
private int nSplitter; //Count of Splited Downloading File 3H4p$\;C
+J.^JXyp0
5l{_E:.1
public SiteInfoBean() 51&wH
{//nSplitter的缺省值为5 8kO|t!?:U
//default value of nSplitter is 5 b4,yLVi<T
this("","","",5); tEf-BV;\y
} 2R|2yAh
0/-[k
R,6?1Z:J
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) HHg=:>L z
{ MZ% P(5
sSiteURL= sURL; qK(?\t$
sFilePath = sPath; S}fIZ1
sFileName = sName; t{x&|%u
this.nSplitter = nSpiltter; M{hA`
'4N[bRCn
(lt/ t
} U/{cYX
)RA7Y}e|m
]+fL6"OD/2
public String getSSiteURL() ){8^l0b
{ %H%>6z x
return sSiteURL; ^H&6'A`
} ]9b*!n<z
H( cY=d,
#?8'Z/1)
public void setSSiteURL(String value) [.3M>,)+-
{ OP``g/x)
sSiteURL = value; :5C9uW#
} GT#iY*
MF%9
IjNE1b$
public String getSFilePath() \kC/)d
{ ]FsPlxk6
return sFilePath; 1/j}VC
} ~e'FPVDn
Eepy%-\
-C.eXR{s
public void setSFilePath(String value) $yc&f(Tv
{ ^\Jg {9a
sFilePath = value; F<G.!Y8!&
} z[CCgs&vqe
`[CXxp
IvH0sS`F
public String getSFileName() MPNBA1s
{ bha_bj
return sFileName; ~Dgui/r9J
} Sh{odrMj*
|)GE7y0Q
=p^*y-z
public void setSFileName(String value) 2nOQ48haT
{ RwY) O5
sFileName = value; &eg]8kV
} rK)%n!Z
S(/@.gI:f
*|hICTWL
public int getNSplitter() \XmtSfFC
{ MqXA8D
return nSplitter; %~$4[,=
} D|_}~T>;&
DF9Br D0{
p2w/jJMD
public void setNSplitter(int nCount) GawLQst[+
{ ZLo3 0*
nSplitter = nCount; sveFxI
} tA'i-D&
} <>2QDI6_
ezHj?@
Nb(se*Y#
/* B/pNM81(
**Utility.java G}] ZZ
*/ evtn/.kDR
package NetFox; +h*&r~T
0^{zq|%Q!
M!mTNIj8~
public class Utility { A5 8i}G9
z?FZu,h}
`p'L3u5H-
public Utility() Y5Ey%Mm6
{ m,]Tl;f
*)u_m h
@{XN}tWDOp
} (7-K4j`
QAcvv 0Hv
//线程睡眠 #`}g?6VHo
public static void sleep(int nSecond) P,tN;c
{ $?I^Dk
try{ 9$S2:2(G
Thread.sleep(nSecond); [yjC@docH
} iY.~N#Q
catch(Exception e) `M"b L|[R
{ "eGS~-DVK
e.printStackTrace (); p72+:I
} E/AM<eN
} }{E//o:Ta
[xM07%:
//日志 SLZv`
public static void log(String sMsg) %l3RM*zb
{ ?mgr#UN
System.err.println(sMsg); kZF\V7k
} {TUCa
{`l]RIig
IcaIB)
public static void log(int sMsg) f{^n<\Jh
{ ^!Bpev
System.err.println(sMsg); ,gD30Pylz
} mX,#|qLf
} } vcr71u
ZOS{F_2.
5p"*nkF
/* t41\nTZr
**TestMethod.java ki}Uw#
*/ G|Q}.v
package NetFox; F-_RL-hbN%
Rp.@
Ia>qVM0
public class TestMethod { ^JYR^X>_
t}NxD`8
& }k=V4L
public TestMethod() l\MiG Na
{ ///xx/weblogic60b2_win.exe FKL}6W:
try{ "D@m/l
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); .[K{;^>
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9HP)@66
SiteFileFetch fileFetch = new SiteFileFetch(bean); Oi l>bv8
fileFetch.start(); l 4~'CLi
} MY1 tYO
catch(Exception e){e.printStackTrace ();} u'?t'I
9chiu%20
AS4m227
} a$;+-Y
:gQc@)jZ(*
kl2]#G(
public static void main(String[] args) x40R)Led
{ Mzxz-cE
new TestMethod(); MZ0uc2L=
} 0r+-}5aSl5
} d7KeJ$xy}p
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