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)); p3r1lUw
} 07dUBoq
for(int i=0;i<nEndPos.length-1;i++) > AV R3b
{ XT5Vo
nEndPos = nStartPos[i+1]; W<uL{k.Kpd
} tKUy&]T
nEndPos[nEndPos.length-1] = nFileLength; ^D0BGC&&
} >MIp r
} K{00 V#
^(0tNX/XD
r,4V SyZF\
//启动子线程 /fM6%V=Y
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (u >:G6K
for(int i=0;i<nStartPos.length;i++) \'L6m1UZ%
{ K,IPVjS
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {&c%VVZb:Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), dkQA[/k
nStartPos,nEndPos,i); : |c,.uO
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); NOa.K)^k
fileSplitterFetch.start(); xUD$i?3z
} 5W!E.fz*T
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), GZc%*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 1Nk}W!v
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [VPqI~u5)
nEndPos = " + nFileLength); ZtEHP`Iin
// fileSplitterFetch[nPos.length-1].start(); z~oGd,
':!;6v|L
#V8='qD
//等待子线程结束 <v('HLA
//int count = 0; `4&\ %9
//是否结束while循环 )vS##-[_
boolean breakWhile = false; 7@vcQv kC
w'5~GhnP+
)M]4p6Y
while(!bStop) $}k"wI[
{ 2+GF:[$
write_nPos(); va;d[D,
Utility.sleep(500); _uHyE }d
breakWhile = true; V_}`2.Pg
~9oS~fP?I
(7ew&u\Li
for(int i=0;i<nStartPos.length;i++) LTtfOcrt
{ O|j5ulO}&"
if(!fileSplitterFetch.bDownOver) -"a+<(Y
{ @R2|=ox
breakWhile = false; NE9e brK
break; O:7y-r0i
} rP`\<}a.
} ooZ7HTP|
if(breakWhile) RFK N,oB
break; {b<8Z*4W
TTE#7\K~B
xJ&StN/'
//count++; :{66WSa@Dd
//if(count>4) 6xFZv t
// siteStop(); Z=F=@<!
} {J0^S
uEi!P2zN
2qr%xK'^B
System.err.println("文件下载结束！"); #Y18z5vo
} |ntJ+
catch(Exception e){e.printStackTrace ();} n)K6Z{x
} ldX]A#d.
E?XA/z !
_ _)Z Q
//获得文件长度 IeU.T@ $
public long getFileSize() x9_ Lt4
{ H7SqM D*y9
int nFileLength = -1; +Zr03B
try{ zIo))L
URL url = new URL(siteInfoBean.getSSiteURL()); mtOrb9`m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); nlY ^
httpConnection.setRequestProperty("User-Agent","NetFox"); gN]`$==c[
MW$9,[
)@Zel.XD
int responseCode=httpConnection.getResponseCode(); "7<4NV@yQ
if(responseCode>=400) X&lkA (
{ GS{9MGl
processErrorCode(responseCode); Qp=uiXs
return -2; //-2 represent access is error Lw#hnLI.
} ,5\n%J:
'QV4=h`
~0}eNz*
String sHeader; 'qM3.U
q(r2\
isd[l-wAmf
for(int i=1;;i++) LTY.i3
{ FCe503qND$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); x9ws@=[:
//Utility.log(in.readLine()); 0?:ZERv
sHeader=httpConnection.getHeaderFieldKey(i); ]t=>#
if(sHeader!=null) u3ZG;ykM
{ Fu`g)#Z
if(sHeader.equals("Content-Length")) I&xRK'
{ Q.|2/6hD7[
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); {'ZnxK'
break; o&AUB`.9~
} A|&EI-In
} VC+\RB#:-
else 1Jd:%+T
break; o+t?OG/0
} soohyK8
} M`<D Z<:<
catch(IOException e){e.printStackTrace ();} 5cADC`q
catch(Exception e){e.printStackTrace ();} f6"j-IW[z
us cR/d
E.6\(^g
Utility.log(nFileLength); ~9c9@!RA2
aj,ZM,Ad
C[pDPx,#:G
return nFileLength; Gt%kok
} 3edAI&a5
4Klfnki
8vRiVJ8QS:
//保存下载信息（文件指针位置） meL'toaJdQ
private void write_nPos() 7h<K)aT
{ 9mnON~j5
try{ 8j$q%g
output = new DataOutputStream(new FileOutputStream(tmpFile)); 4 5lg&oO
output.writeInt(nStartPos.length); bDo'hDmW
for(int i=0;i<nStartPos.length;i++) 'KL(A-}!
{ Jc)1}
// output.writeLong(nPos); @CmxH(-i-
output.writeLong(fileSplitterFetch.nStartPos); J$Q-1fjj
output.writeLong(fileSplitterFetch.nEndPos); hmH$_YP}
} )yP>}ME
output.close(); zaZ}:N/w(z
} f+6l0@K2
catch(IOException e){e.printStackTrace ();} ;x#>J +QlG
catch(Exception e){e.printStackTrace ();} m&q;.|W
} fUL"fMoU
JK(&E{80
$ZU(bEUOG
//读取保存的下载信息（文件指针位置） jveRiW@
private void read_nPos() %awS*
{ K9q~Vf
try{ q T].,?
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ASvPr*q/
int nCount = input.readInt(); IMZKlU3
nStartPos = new long[nCount]; taQ[>x7b
nEndPos = new long[nCount]; 3(:mRb}
for(int i=0;i<nStartPos.length;i++) + LwoBn>6
{ >D<=9G(a
nStartPos = input.readLong(); h 3&:"*A2
nEndPos = input.readLong(); Z@ kC28
} aK{\8L3]
input.close(); DVJc-.x8
} 1Tq$E[
catch(IOException e){e.printStackTrace ();} ej;taKzj
catch(Exception e){e.printStackTrace ();} dx}/#jMa
} 2YKM9Ks
)US/bC!M$
4AYc8Z#'
private void processErrorCode(int nErrorCode) 9pcf jx..
{ ~@D%qbN
System.err.println("Error Code : " + nErrorCode); lt4jnV2"a
} /09=Tyy/\
bJm0
(weokP!
//停止文件下载 Y14R"*t~
public void siteStop() (;&?B.<\:
{ kZ9<j+.
bStop = true; G)hH?_U#T
for(int i=0;i<nStartPos.length;i++) N o(f0g.
fileSplitterFetch.splitterStop(); ogqV]36Idh
u;Eu<jU1
P|4E1O
} EcoUpiL%2
} e@=[+iJc
//负责部分文件的抓取 rx>Tc#g
**FileSplitterFetch.java IWqxT?*
*/ #2jn4>
package NetFox; fVUBCu
]B3FTqR{i
i\;&CzC:
import java.io.*; jF{gDK
import java.net.*; I#t9aR+&
m5w9l"U]H
U;{,lS2l
public class FileSplitterFetch extends Thread { Y@H,Lk
:{:?D\%6
yvWzc uL#
String sURL; //File URL ^HFU@/
long nStartPos; //File Snippet Start Position i @9Qb
long nEndPos; //File Snippet End Position hlFU"u_
int nThreadID; //Thread's ID 3B".Gsm)X
boolean bDownOver = false; //Downing is over 9/daRq$
boolean bStop = false; //Stop identical a^c,=X3
FileAccessI fileAccessI = null; //File Access interface _8li4;F
u45h{i-e
*{dD'9Bg
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5u)^FIBj
{ `s83rhs`!
this.sURL = sURL; RO$@>vL
this.nStartPos = nStart; RA/ =w&
this.nEndPos = nEnd; 8U2wH
nThreadID = id; Ag#5.,B-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 B N*,!fx
} e0N=2i?I#z
).+xcv
jaO#><f
public void run() 9[p}.9/
{ GQ-e$D@SfB
while(nStartPos < nEndPos && !bStop) 0Dm`Ek3A7x
{ Fm$n@RbX
oyN+pFVB:$
y>7VxX0xi
try{ FJjF*2.
URL url = new URL(sURL); W_BAb+$aF
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z|:_c
httpConnection.setRequestProperty("User-Agent","NetFox"); GATP
String sProperty = "bytes="+nStartPos+"-"; 4-M6C 5#.
httpConnection.setRequestProperty("RANGE",sProperty); VJl &Bq+
Utility.log(sProperty); XuFm4DEJ
c;21i;&,9
[2QY
InputStream input = httpConnection.getInputStream(); mU?&\w=v$
//logResponseHead(httpConnection); |P. =
y13CR2t6
1RI#kti-"
byte[] b = new byte[1024]; nF. ;LM
int nRead; .}$`+h8WT
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 4lY&=_K[)
{ ^;)SFmjg%
nStartPos += fileAccessI.write(b,0,nRead); U=c5zrs
//if(nThreadID == 1) Nn,vdu{^2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); z6FbM^;;
} |%:qhs,
t7*G91Hoq&
2w x[D
Utility.log("Thread " + nThreadID + " is over!"); Y uw E 0
bDownOver = true; (!_X:+0_
//nPos = fileAccessI.write (b,0,nRead); AF*ni~
} l${Hgn+
catch(Exception e){e.printStackTrace ();} uFrJ:l+
} %;=IMMK
} $vgmoJ@X0
,);= (r9
|i}+t
//打印回应的头信息 I*+LJy;j
public void logResponseHead(HttpURLConnection con) EBj,pk5M
{ d739UhKC
for(int i=1;;i++) rSF;Lp)}
{ q(ZB.
String header=con.getHeaderFieldKey(i); RR~sEUCo{
if(header!=null) w L/p.@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); k Z+q
Utility.log(header+" : "+con.getHeaderField(header)); zH=/.31Q
else -+ ]T77r
break; _ bXVg3oDt
} Z9J =vzsHE
} S|{Yvyp
wL8bs- U
(1kn):
public void splitterStop() 'uP'P#
{ (opROsFh
bStop = true; jpYw#]Q
} fH#F"^A
OQytgXED
|aI|yq)
} IL+#ynC
4DQ07w
bK_0NrXP
/* ==-7F3QP
**FileAccess.java =1{H Sf
*//文件访问(定位，写) 7X9+Qj;
package NetFox; $I)Tk`=
import java.io.*; g( ]b\rj
8Z9MD<RLw
RR[)UQ
public class FileAccessI implements Serializable{ ;_?zB NW
'WKu0Yi^'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "B|nhd
RandomAccessFile oSavedFile; dxzvPgi?
long nPos; 26\HV
G?Qe"4 .
L?3VyBE
public FileAccessI() throws IOException l]a^"4L4`o
{ W\I$`gyC/
this("",0); 4)z3X\u|Z2
} T8,k77
ALE808;|
D:YN_J"kV
public FileAccessI(String sName,long nPos) throws IOException 8_^'(]
{ uD.
oSavedFile = new RandomAccessFile(sName,"rw"); >Jm-2W5J
this.nPos = nPos; {Ior.(D>Y
oSavedFile.seek(nPos); ~&wXXVK3
} E@5zd@[
652uZ};e
bjM-Hd/K
public synchronized int write(byte[] b,int nStart,int nLen) K?h[.`}
{ 'sm[CNzS
int n = -1; ~u_K&X
try{ 17V\2=Io
oSavedFile.write(b,nStart,nLen); c^ixdk
n = nLen; &_Cxv8
} >QYh}Z-/%
catch(IOException e) r\A@&5#q
{ HO266M
e.printStackTrace (); 89*S?C1
} bh=\
J>f /u:.
3q'K5} _
return n; ~fyF&+ibp'
} #@nZ4=/z
httls>:xB|
y-E1]4?})
} z7'n, [
]sX7%3P
Nbgp_:{
/* $se !8s"
**SiteInfoBean.java Y;fuh[#
*/ Am2*-
package NetFox; y,'FTP9?
<h'8w
#Y;.>mF
public class SiteInfoBean { 8pXfT%]
mBw2
umJay/>
private String sSiteURL; //Site's URL M.o?CX'
private String sFilePath; //Saved File's Path i FC"!23f
private String sFileName; //Saved File's Name =^BqWC2~
private int nSplitter; //Count of Splited Downloading File o8w-$ Qb
cj$,ob&DX
-0A@38, }
public SiteInfoBean() YEg .
{//nSplitter的缺省值为5 q:xtm?'$
//default value of nSplitter is 5 Ly^E& ,)
this("","","",5); X32RZ9y
} 5\uNEs$T
*}+R{
FpP\-+Sl
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ,)Yao;Cvd
{ r`?&m3IOP
sSiteURL= sURL; cge-'/8w%
sFilePath = sPath; V%i<;C
sFileName = sName; ZkwJ.SuU
this.nSplitter = nSpiltter; B#J{F
$`E4m8fX
Bfbl#ZkyL
} jIKBgsiF/
cYsR0#
@[n2dmj
public String getSSiteURL() Us1@\|]
{ !.9l4@z#
return sSiteURL; 5r'=O2AZX
} Sq?,C&LsA
EJO.'vQ
C#Y,r)l
public void setSSiteURL(String value) 4DvdEt
{ .8-PB*vb
sSiteURL = value; O:2 #_
} Tsu\oJ[
b21}49bHN
#1MKEfv(~
public String getSFilePath() 55LgBD
{ @=CLeQG`
return sFilePath; $Xf~# uH
} X>2? `8M
mG X\wta
P<8LAc$T
public void setSFilePath(String value) )sqaR^
{ `$H7KIG
sFilePath = value; o\d |CE;>
} TV? ^c?{5
n:F@gZd`
#U\$@4D
public String getSFileName() t/A:k
{ Pv#KmSA9
return sFileName; 6s'[{Ov
} VZ;@S3TS
e,^pMg~
}Bd_:#.mw
public void setSFileName(String value) xOhRTxic
{ e!6eZ)l
sFileName = value; ubD#I{~J
} %@>YNPD`E
#sL/y
dZF8R
public int getNSplitter() 'HCnB]1
{ ^<!Ia
return nSplitter; S=4R5igrC
} V_jiOT!
+5#x6[
!TGr.R
public void setNSplitter(int nCount) P?xA$_+
{ U8E0~[y'
nSplitter = nCount; *jGPGnSo
} (yfXMp,x
} r9<V%PHv
fa"\=V2S
ZH% we
/* Ohc^d"[7
**Utility.java OqtQA#uL
*/ )q^(T1
package NetFox; 0Qt~K#mr/
,b$z!dvhl
Ac J>$L)
public class Utility { 1p~5h(jI
)mj<{Td`
l4zw]AYk+X
public Utility() ,eDu$8J9
{ h:_NA
{QMN=O&n
O 3G:0xF
} )x)gHY8;
% ^e@`0L
//线程睡眠 pVY4q0@
public static void sleep(int nSecond) Q@3B{
{ wBLsz/
try{ ZH!;z-R
Thread.sleep(nSecond); }H5/3be
} ZxI]I1)
catch(Exception e) &eU3(F`.
{ GZ <nXU>
e.printStackTrace (); W|0My0y
} sSNCosb
} f*v1J<1#
{|Bd?U;
//日志 \,hrk~4U;(
public static void log(String sMsg) %oR>Uo
{ 2!BsEvB(
System.err.println(sMsg); 6oYIQ'hc
} pG~'shD~Dn
.izf#r:<
6vF/e#},
public static void log(int sMsg) $Vsy%gA<
{ i]dz}=j'
System.err.println(sMsg); IEc>.J|T&
} 4aA9\\hfGY
} *N`;I@Q"[
a/:]"`)
Q4=|@|U0
/* ;sCU[4
**TestMethod.java U[bgu#P;
*/ 0_Lm#fE U
package NetFox; q1jN]H
!8o\.uyi
ZOC#i i`:
public class TestMethod { F'rt>YvF
T30Zk*V
",T`\8&@e
public TestMethod() h^Qh9G0dn
{ ///xx/weblogic60b2_win.exe >J>>\Y(p
try{ lAz2%s{6
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Psp^@
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Y|:YrZSC
SiteFileFetch fileFetch = new SiteFileFetch(bean); m!0N"AjA
fileFetch.start(); $M39 #a
} H@Q`
catch(Exception e){e.printStackTrace ();} ![).zi+m
}f]b't
7pP+5&*
} 5=Suj*s{D#
4QO/ff[ o
$e*B:}x}
public static void main(String[] args) d-h"JZ9
{ UP]1(S?
new TestMethod(); "1K:/n
} #cO+<1
} i+1Qf
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