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)); WSi`)@.XO
} Qz\yoI8JA,
for(int i=0;i<nEndPos.length-1;i++) 11[[HkX@
{ usH9dys,
nEndPos = nStartPos[i+1]; I_6NY,dF
} ,yus44w[
nEndPos[nEndPos.length-1] = nFileLength; M.$Li#So,
} g@wF2=
} qYR $5
N-`Vb0;N
|I-;CoAg
//启动子线程 ~qt)r_jW
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3:@2gp!tq
for(int i=0;i<nStartPos.length;i++) Jz7a|pgep
{ hr_ 5D
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), aDmyr_f$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'kb5pl~U
nStartPos,nEndPos,i); mbB,j~;^6H
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g\S@@0T{0
fileSplitterFetch.start(); (DJLq
} :Rv?>I j
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), r8g4NsRVtv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ;iR( Ir
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", tvXoF;Yq
nEndPos = " + nFileLength); RO[Ko-m|/N
// fileSplitterFetch[nPos.length-1].start(); J ^gtSn^
HM57b>6
1+6:K._C(m
//等待子线程结束 JTK>[|c9oE
//int count = 0; *p:`F:
//是否结束while循环 kP~'C'5Ys
boolean breakWhile = false; %Xs3Lz
wmKM:`&[5
@ODwO;_R5
while(!bStop) E .^5N~.
{ f2Zi.?``H
write_nPos(); CT,caa
Utility.sleep(500); DP\s-JpI[
breakWhile = true; ?T=]?[
!+T\}1f7d
OLh`R]Sd
for(int i=0;i<nStartPos.length;i++) |$"2R3
{ nX4R
if(!fileSplitterFetch.bDownOver) ]T|9>o!
{ Xou1X$$z
breakWhile = false; [p[nK=&r
break; j(^ot001%v
} (Cjnf a 2
} ^7MhnA
if(breakWhile) &7Frg`B&:
break; AzAD76iNv
\$:KfN>WY
Fx,08
//count++; ~f=~tN)hZ
//if(count>4) !<r+h,C
// siteStop(); hoY.2 B_
} ah<1&UG,
o&uO]
I@Zd<Rn
System.err.println("文件下载结束！"); <X[TjP
} h/~:}Bof
catch(Exception e){e.printStackTrace ();} r>73IpJI
} #p&&w1
!Ic;;<
4;"^1 $
//获得文件长度 r_C|gfIP
public long getFileSize() x,$N!X
{ J-*&&
int nFileLength = -1; W}m-5L
try{ ! |SPOk
URL url = new URL(siteInfoBean.getSSiteURL()); qu]ch&"?U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b`"E(S/
httpConnection.setRequestProperty("User-Agent","NetFox"); Ci%u =%(
o?nlnoe
M|!^ #!a(
int responseCode=httpConnection.getResponseCode(); L9tjHC]
if(responseCode>=400) }OY]mAv-B
{ H.-jBFt}
processErrorCode(responseCode); ~RcI+jR)
return -2; //-2 represent access is error 5/x"!Jk
} Rs+rlJq
BiGB<Jr
p@epl|IZp
String sHeader; 50!/%
w-2&6o<n-
QZy+`
for(int i=1;;i++) RmS|X"zc
{ x._IP,vRx^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); sYV7t*l
//Utility.log(in.readLine()); []HMUL]"
sHeader=httpConnection.getHeaderFieldKey(i); !iKR~&UpAL
if(sHeader!=null) DxjD/?R8
{ JQ{g'cT
if(sHeader.equals("Content-Length")) m87,N~DP
{ D'V0b"
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); .K?',x
break; wMy$T<:
} m"Y;GzqQl
} .C^1.)
else DLMG<4Cd~
break; g\MHv#v*k
} Pn@k)g
} Ol,;BZHc\
catch(IOException e){e.printStackTrace ();} rfqw/o
catch(Exception e){e.printStackTrace ();} xdWfrm$;ZA
(;utiupW
d,=Kv
Utility.log(nFileLength); /lAB
Enee\!@v
~;St,Fw<<
return nFileLength; "zW3dKVc
} =4GJYhj
(]wi^dE
b?Wg|D
//保存下载信息（文件指针位置） K/RQ-xd4
private void write_nPos() jvx9b([<sG
{ J6x\_]1:*
try{ /64jO?mp
output = new DataOutputStream(new FileOutputStream(tmpFile)); &tY3nr
output.writeInt(nStartPos.length); ;/i"W
for(int i=0;i<nStartPos.length;i++) u2HkAPhD
{ 9tZ)#@\
// output.writeLong(nPos); 9xWC<i
output.writeLong(fileSplitterFetch.nStartPos); xsK{nM6g
output.writeLong(fileSplitterFetch.nEndPos); %bf+Y7m
} TJ(PTB;
output.close(); `x:znp}'
} qh Ezv~
catch(IOException e){e.printStackTrace ();} A^7!:^%K
catch(Exception e){e.printStackTrace ();} YArNJ5z=
} x4v@Kk/
N[4v6GS
}HS:3Dt
//读取保存的下载信息（文件指针位置） kg[u@LgvoN
private void read_nPos() tq=1C=h
{ "sLdkd}dj
try{ ={' "ATX(U
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~XGO^P"?
int nCount = input.readInt(); '^'4C'J
nStartPos = new long[nCount]; C("PCD
nEndPos = new long[nCount]; uY0V!W
for(int i=0;i<nStartPos.length;i++) CG'NC\x5
{ &{QB}r
nStartPos = input.readLong(); @k~?h=o\b
nEndPos = input.readLong(); ToNi<~
} A(duUl~
input.close(); >yvP[$]!6
} T=cSTS!P;q
catch(IOException e){e.printStackTrace ();} {ZFa +
catch(Exception e){e.printStackTrace ();} $,08y
} H3{x;{.b
xO'I*)
8xhXS1
private void processErrorCode(int nErrorCode) 4mOw[}@A
{ PpMZ-f@
System.err.println("Error Code : " + nErrorCode); 7SzY0})<U
} Q0~5h?V'
M<JJQh5
Z+ubc"MVb
//停止文件下载 mY-Z$8r
public void siteStop() a?'3
{ ;ak3@Uee
bStop = true; 3ojK2F(1D
for(int i=0;i<nStartPos.length;i++) .fcU&t
fileSplitterFetch.splitterStop(); 04tUf3>
AIsM:sV]
FD(zj^*
} RAKQ+Y"nl
} 992;~lBu
//负责部分文件的抓取 QiWv
**FileSplitterFetch.java 1!8*mk_R{
*/ q3Umqvl)oe
package NetFox; G],+?E_,
~WuElns
vl$! To9R"
import java.io.*; >7!aZO
import java.net.*; s#w+^Mw$
TI}H(XL(
vZ 4Z+;.
public class FileSplitterFetch extends Thread { k/l@P
4,9AoK)yp
=f@O~nGm
String sURL; //File URL tYIHsm\b
long nStartPos; //File Snippet Start Position IyG5Rj2
long nEndPos; //File Snippet End Position (PGmA>BT
int nThreadID; //Thread's ID (Br$(XJoK}
boolean bDownOver = false; //Downing is over $N;!. 5lX3
boolean bStop = false; //Stop identical Lhl)pP17
FileAccessI fileAccessI = null; //File Access interface |Ix6D
x$CpUy{6
V2es.I
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException zcJ]US
{ G_5sF|(mq
this.sURL = sURL; Z{#^lhHx
this.nStartPos = nStart; IZ')1
this.nEndPos = nEnd; )|LX_kyW
nThreadID = id; !|_ CXm T|
fileAccessI = new FileAccessI(sName,nStartPos);//定位 y- k?_$M
} 7^sU/3z
w|WZEu:0|
A`(p6 H"s
public void run() bI[!y#_z4
{ +WPi}
while(nStartPos < nEndPos && !bStop) V.WfP*~NJ
{ S "oUE_>
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a2/r$Tgm
try{ <6<uO\B\
URL url = new URL(sURL); w:FH2*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jbIWdHZ/US
httpConnection.setRequestProperty("User-Agent","NetFox"); Z.6`O1OY}?
String sProperty = "bytes="+nStartPos+"-"; :'y
httpConnection.setRequestProperty("RANGE",sProperty); >|0yH9af
Utility.log(sProperty); N)Qj^bD!
1ISA^< M
m?<8 ':
InputStream input = httpConnection.getInputStream(); R $'}Z
//logResponseHead(httpConnection); ?y<n^`
XeDU ,
I#eIm3Y?
byte[] b = new byte[1024]; xHsH .f_{
int nRead; yE9JMi0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6(9Ta'ywZ
{ 1@)]+* F*z
nStartPos += fileAccessI.write(b,0,nRead); {DNc7G
//if(nThreadID == 1) SNvK8,"g
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); *(?YgV
} C*Ws6s>+z
BT>*xZLpS
p<*-B
Utility.log("Thread " + nThreadID + " is over!"); <eN>X:_N
bDownOver = true; uNd;;X
//nPos = fileAccessI.write (b,0,nRead); \(T;@r
} ?;)(O2p
catch(Exception e){e.printStackTrace ();} vCH>Fj"7
} ^e@c Ozt
} gEKJrAA
}/c.>U
S-2xe?sb
//打印回应的头信息 ?[!.TU?4N
public void logResponseHead(HttpURLConnection con) )2S0OY.
{ ""pJO 6bI
for(int i=1;;i++) 4n3QW%#
{ 2IjqTL
String header=con.getHeaderFieldKey(i); YD@V2gK
if(header!=null) tB(Q-c
//responseHeaders.put(header,httpConnection.getHeaderField(header)); !c6lP'U
Utility.log(header+" : "+con.getHeaderField(header)); VPN@q<BV
else 7/Lbs
break; [-6j4D
} qgZ(o@\
} h(/|`
](MXP,R
@Jm$<E
public void splitterStop() fvit+
{ oPa2GW8
bStop = true; *qOo,e
} d1y(Jt
-HoPECe
J=zZGd%
} 8w2+t>?
?9?0M A<[i
; UrwK
/* DVSYH{U4
**FileAccess.java A1Q]KS@
*//文件访问(定位，写) 2#+@bk>^{
package NetFox; 00;=6q]TA
import java.io.*; uU5:,Wy+dg
Tr@`ozp8
Kq{s^G
public class FileAccessI implements Serializable{ bO2$0!=I
?WAlW,H>
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 $%1[<}<
RandomAccessFile oSavedFile; Q8:u1$}
long nPos; PI?-gc?[
JC=Bxv
{ReAl_Cm
public FileAccessI() throws IOException |AFF*]e S
{ )3)L
this("",0); H>M%5bj
} 8kMMQES
kJDMIh|g
t4gD*j6J3
public FileAccessI(String sName,long nPos) throws IOException sp_(j!]jX
{ 7FMHz.ZRE
oSavedFile = new RandomAccessFile(sName,"rw"); %{}Jr`
this.nPos = nPos; k ,<L#?,a
oSavedFile.seek(nPos); 0.@/I}R[
} #h r!7Kc;N
}Bc6:a
~7~nU>Vv
public synchronized int write(byte[] b,int nStart,int nLen) c&0IJ7fZG
{ Pi8U}lG;
int n = -1; a?JU(
try{ x(S064
oSavedFile.write(b,nStart,nLen); tY[y?DJ
n = nLen; *\joaw
} q1?2 U<
catch(IOException e) x7NxHTL
{ RIJBHOa
e.printStackTrace (); q!AS}rV
} |fw+{f
{Or|] 0
,/d-o;W
return n; KO5Q;H
} " g_\W
CiMy_`H
3i s.c)
} o1n c.2/0J
_puQX@i
gsU&}R1*h
/* *g=*}2
**SiteInfoBean.java Mb<KZ_wYOX
*/ QPFpGS{d
package NetFox; $~:hv7%
4uu*&B
wPc,FH+y
public class SiteInfoBean { Zy!\=-dSm
~Yr.0i.W
(>8fcQUBb
private String sSiteURL; //Site's URL N@A#e/8
private String sFilePath; //Saved File's Path IsRsjhg8x
private String sFileName; //Saved File's Name @ym7hk.
private int nSplitter; //Count of Splited Downloading File Yb?#vpI
o&CvjE
\/$v@5
public SiteInfoBean() F(XWnfUv
{//nSplitter的缺省值为5 ,U7hzBj8k
//default value of nSplitter is 5 `nizGg~1
this("","","",5); mYy3KqYu
} R 7{rY
:ZzG5[o3
O!j@8~='
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p[/n[@<8=
{ XBr>K>(
sSiteURL= sURL; z?gJHN<
sFilePath = sPath; HFDg@@
sFileName = sName; ]3I_H+hU
this.nSplitter = nSpiltter; N9*$'
tP:xx2N_
RV($G8U
} k[zf`x^
?.Kl/8ml
>eEf|tKO
public String getSSiteURL() 4o=G) KO{
{ 8WyG49eic
return sSiteURL; 'rF TtT
} 6XG+YIG6w
-[7.VP
G6J3F
public void setSSiteURL(String value) K3Xy%pqR#
{ *Z0}0< D@Z
sSiteURL = value; 2xnOWW
} hT Xc0
Mr1pRIYMd
s e1ipn_A
public String getSFilePath() 9z-"JnM
{ pTN_6=Y"
return sFilePath; Jg Xbs+.
} Zg'[.wov
2 43DdIG$
"*T)L<G
public void setSFilePath(String value) [cH/Y2[
{ {otvJ|'N
sFilePath = value; '*-SvA\Cx
} I&vB\A
~kHir]jc
/;lk.-yU
public String getSFileName() l9jcoVo.
{ dKMuo'H'%
return sFileName; 2MC\~"L<
} 81n%2G
TcIUo!:z
P*LcWrK
public void setSFileName(String value) dqkkA/1
{ 4 '+)9&g
sFileName = value; [L\w]6
} MVj@0W33m
k]JLk"K
s R~&S))
public int getNSplitter() %z.G3\s0
{ %z2nas$$g
return nSplitter; F+6ZD5/
} p!691LI
O3_Mrn(R
!of7]s
public void setNSplitter(int nCount) jab]!eY
{ V|D;7
nSplitter = nCount; nJ?C4\#3
} >YW>=5_
} -`;8~wMN
_+. t7q^
u,pm\
/* {NFeX'5bP
**Utility.java y, Z#?O
*/ 3xe8DD
package NetFox; -`RJk(
Y!`?q8z$G
V.4j?\#%
public class Utility { GWW@8GNI
^Y&Cm.w
Za} |Ee
public Utility() m^=, RfUUd
{ f4_\F/
izKk@{Md
5A)w.i&V
} GBQb({
`%=Jsi0.Nq
//线程睡眠 bXW)n<y
public static void sleep(int nSecond) l=oVC6C
{ x B?:G
try{ -r2cK{Hhp&
Thread.sleep(nSecond); cU>&E*wD
} 7mjj%
catch(Exception e) bDkE*4SRX
{ 8N`$7^^
e.printStackTrace (); `8-aHPF-
} d5%*^nMpY
} 1^;h:,e6
zbR.Lb
//日志 d3$<|mG$
public static void log(String sMsg) Lr^xp,_n
{ g IKm
System.err.println(sMsg); w?*KO?K
} PYUY bRn
DG-vTr
GKSy|z
public static void log(int sMsg) Q.XsY.{
{ ,dp?'_q{
System.err.println(sMsg); K4yYNlY
} =gn}_sKNE
} Jv<)/Km`
=, 0a3D6b
9e&#;6l
/* F:g{rm[
**TestMethod.java 3azc`[hl
*/ )eEvyU
package NetFox; p^:Lj9Qax
#R8l"]fxr?
Z)A+ wM
public class TestMethod { V[M#qZS
VB\6SG
9c^EoYpy-
public TestMethod() "{k )nr+7U
{ ///xx/weblogic60b2_win.exe of`]LU:
try{ "6dbRo5%
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Zz-;jkX)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 55DzBV
SiteFileFetch fileFetch = new SiteFileFetch(bean); Vr1|%*0Tv
fileFetch.start(); >l1Yhxd_0*
} IpJv\zH7
catch(Exception e){e.printStackTrace ();} qtN29[x
I`TD*D
!S!03|
} @qDrTH]5
@,&m`qzd+
@>@Nug2
public static void main(String[] args) QL2y,?Mz7
{ B|=maz:_
new TestMethod(); aTm.10{^
} weV#%6=5\
} pCUOeQL(
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