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)); t[yu3U
} f=f8)+5
for(int i=0;i<nEndPos.length-1;i++) pm.Zc'23
{ ioZ{2kK
nEndPos = nStartPos[i+1]; YKk*QcAn
} VPAi[<FzOG
nEndPos[nEndPos.length-1] = nFileLength; ("+J*u*kq_
} Kpx(x0^2
} RF,[1O-\O
!pwY@}oL
bIR&e E
//启动子线程 }\s\fNSQ/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; E5H0Yo.Wi
for(int i=0;i<nStartPos.length;i++) hyPVt6Gkj
{ v*pN~}5
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), &ml7368@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {&bjjM
nStartPos,nEndPos,i); V2&O]bR
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zK5/0zMZ
fileSplitterFetch.start(); A5A4*.C
} +;ILj<!Z7
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), C1V@\mRi
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); _(R1En1
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", a(qij&>
nEndPos = " + nFileLength); ;nDCyn4i]
// fileSplitterFetch[nPos.length-1].start(); 3kc.U
zOEdFU{x
R;6$lO8C&
//等待子线程结束 m4=[e!
//int count = 0; sX :)g>b
//是否结束while循环 ?hXeZB+b4
boolean breakWhile = false; VX;br1$X
g$(<wWsU
3)bC,
while(!bStop) ,?OWwm&J
{ O:'ENoQ:&
write_nPos(); \9Z1'W
Utility.sleep(500); pr;z>|FgA>
breakWhile = true; &N`s@Ka
K]
mw[T[
for(int i=0;i<nStartPos.length;i++) HVq02 Z
{ ;AjY-w
if(!fileSplitterFetch.bDownOver) 2!7)7wlj0
{ sghQ!ux
breakWhile = false; s"7$SxMT
break; q$<M2
} KliMw*5(
} !ULU#2'1
if(breakWhile) nz?jNdyz
break; pKnM=N1f
3>+9Rru
Tx+Bkfj
//count++; aLWNqe&1
//if(count>4) swfcA\7R
// siteStop(); 3Y L
} Hju7gP=y}
lU}y%J@
QO-R>
System.err.println("文件下载结束！"); >R9_;
} Zs(I]^w;d
catch(Exception e){e.printStackTrace ();} 6rx%>\UkS
} `2B,+ytW8
QXQ'QEG
e1EFZ,EcaO
//获得文件长度 kPt] [1jo
public long getFileSize() y,i ~w |4
{ 5 aT>8@$Z^
int nFileLength = -1; o`]o(OP
try{ ZSBa+3;z
URL url = new URL(siteInfoBean.getSSiteURL()); l\?HeVk^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o/;kzi
httpConnection.setRequestProperty("User-Agent","NetFox"); w`N|e0G@
B;3lF;3`
|SO?UIWp
int responseCode=httpConnection.getResponseCode(); 'R{XqHP
if(responseCode>=400) sW53g$`v
{ H(JgqbFB*
processErrorCode(responseCode); &gNb+z+
return -2; //-2 represent access is error nO^m
} R.Plfm06Ue
i>]1E^yF
wfecM(
String sHeader; 7M|!N_ $
$RFy9(>
R>r@I_
for(int i=1;;i++) t,YnweH
{ ^tw\F7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3!&PI
//Utility.log(in.readLine()); o!\Q,
sHeader=httpConnection.getHeaderFieldKey(i); ')bas#=uP
if(sHeader!=null) HFtl4P
{ ed=pRb
if(sHeader.equals("Content-Length")) s!vvAD;\
{ O!,WH?r
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); go6XUe
break; {pV\]E\]
} SRUg2)d
} /8)-j}gZa
else 4/z K3%J
break; xla64Qld
} !mM`+XH
} H/rJ:3
catch(IOException e){e.printStackTrace ();} aB=&XGV9
catch(Exception e){e.printStackTrace ();} n]15 ~GO.
MHuQGc"e+4
Xscm>.di
Utility.log(nFileLength); WDM^rjA|j
JlM0]__v
4*)a3jI?
return nFileLength; ^B>BA
} 4TPAD)C
d){o#@
YqJ `eLu
//保存下载信息（文件指针位置） w,6zbI/
private void write_nPos() WN5`zD$
{ b3h3$kIYN
try{ p4Wy2.&Q
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8)NQt$lWp
output.writeInt(nStartPos.length); lBYc(cr
for(int i=0;i<nStartPos.length;i++) feSj3,<!
{ \V1geSoE
// output.writeLong(nPos); 4 8}\
output.writeLong(fileSplitterFetch.nStartPos); $N}nO:`t
output.writeLong(fileSplitterFetch.nEndPos); ZFJqI
} xT]|78h$
output.close(); )jS9p~FS
} hk +@ngh%
catch(IOException e){e.printStackTrace ();} ]c Or$O*
catch(Exception e){e.printStackTrace ();} b3zxiq x
} s`Y8&e.Yr
-msfiO
']x`d
//读取保存的下载信息（文件指针位置） ' )0eB:
private void read_nPos() F*0rpQ,*
{ qwERy{]Sp;
try{ [110[i^
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %u)niY-g
int nCount = input.readInt(); 1+{V^)V?
nStartPos = new long[nCount]; JKXb$
nEndPos = new long[nCount]; ,>AA2@6zMT
for(int i=0;i<nStartPos.length;i++) N084k}io
{ "1-gMob
nStartPos = input.readLong(); q2pq~LI
nEndPos = input.readLong(); +(pFU\&U3H
} HW@r1[Y
input.close(); `veq/!
} ]ZbZ]
catch(IOException e){e.printStackTrace ();} mZ[tB/
catch(Exception e){e.printStackTrace ();} .$rt>u,8<
} e2}5< 7
Os5Xejh`I
@[s+5_9nk
private void processErrorCode(int nErrorCode) %xJ6t5.-
{ *!wBn
System.err.println("Error Code : " + nErrorCode); Jn+k$'6%#
} 3jJd)C R
RyN}Gz/YN
/_?y]Ly[r
//停止文件下载 d4r@Gx%BE
public void siteStop() gQ0W>\xz
{ Cb1fTl%
bStop = true; KiaQ^[/q
for(int i=0;i<nStartPos.length;i++) *%(BE*C}
fileSplitterFetch.splitterStop(); [8h~:.d`
QrX 5Kwq
B< 6E'
} 8etNS~^
} U.kTdNSp
//负责部分文件的抓取 "h84D&V
**FileSplitterFetch.java G(*7hs
*/ S+LS!b
package NetFox; O^_$cq
fPj*qi
9P)28\4
import java.io.*; W,53|9b@
import java.net.*; Wb;x eG
k/`WfSM\.
<jk.9$\$A
public class FileSplitterFetch extends Thread { 0c,)T1NG>
Vi5&%/Y
pAY[XN
String sURL; //File URL %z_L}L
long nStartPos; //File Snippet Start Position yf/c
long nEndPos; //File Snippet End Position vr$zYdV>
int nThreadID; //Thread's ID M#5*gWfq9
boolean bDownOver = false; //Downing is over !ot$Q
boolean bStop = false; //Stop identical ?%]?#4bkc
FileAccessI fileAccessI = null; //File Access interface mD]^a;U[X
Cbq|<p# #o
Z4ZR]eD
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _l$1@
{ pn._u`xMV
this.sURL = sURL; Fb^Ae6/i
this.nStartPos = nStart; $YPQi.
this.nEndPos = nEnd; x392uS$#
nThreadID = id; jWX^h^n7K
fileAccessI = new FileAccessI(sName,nStartPos);//定位 G^6\OOSy
} D$vP&7pOr4
fN-y8
XVRtfo
public void run() AgU 7U/yk
{ B|zVq=l~
while(nStartPos < nEndPos && !bStop) h]w5N2$}?
{ _XP3|E;I/
pRTdP/(OQ
.o"FT~}z
try{ xtN=?WjVe0
URL url = new URL(sURL); 3v:c".O2O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J_tI]?jrU
httpConnection.setRequestProperty("User-Agent","NetFox"); OM1pyt
String sProperty = "bytes="+nStartPos+"-"; % QKlvmI"
httpConnection.setRequestProperty("RANGE",sProperty); uTq)Ets3
Utility.log(sProperty); M?FbBJ`sF
`BGU
n@e[5f9?x
InputStream input = httpConnection.getInputStream(); oKlOcws}
//logResponseHead(httpConnection); zB@@Gs>
$At,D.mGkb
}aJK^>^>A
byte[] b = new byte[1024]; xdV $dDCT
int nRead; WER\04%D\m
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 8>(DQ"h
{ zm9_[0
nStartPos += fileAccessI.write(b,0,nRead); DP-euz
//if(nThreadID == 1) *K}j>A
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); L3 VyW8Y
} HHMv%H]M
YYiT,Xp<A
P:3%#d~q
Utility.log("Thread " + nThreadID + " is over!"); \NN5'DBx
bDownOver = true; |AS`MsbI9
//nPos = fileAccessI.write (b,0,nRead); `J}-U\4F{
} 320g!r
catch(Exception e){e.printStackTrace ();} ?->&)oAh
} "v9i;Ba>+
} YJ[Jo3M@j0
c~=yD:$
0s%rd>3
//打印回应的头信息 R8K?!Z
public void logResponseHead(HttpURLConnection con) ~H+W[r}
{ GSh~j-C'
for(int i=1;;i++) 4-dV%DgC
{ {k#RWDespy
String header=con.getHeaderFieldKey(i); 4\?GA`@
if(header!=null) C $r]]MSj
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ?{bAyh/
Utility.log(header+" : "+con.getHeaderField(header)); *wY { ~zh
else nOE 1bf^l
break; kpU-//lk+
} ti}g?\VT
} 5 Y|(i1
Ksu_4dE
/t<C_lLM
public void splitterStop() m@W\Pic,j.
{ HxXCxI3
bStop = true; nP+]WUnY
} zs_^m1t1s
,aLdW,<6
0k7kmDW
} ~=pAy>oV
_H(:$=$Q
@jp}WwC/
/* eK]$8l|LI
**FileAccess.java IUJRP
*//文件访问(定位，写) fsxZQ=-PW
package NetFox; ]PI|Xl
import java.io.*; !KEnr`O2u
xqAXfJ.
e#uk+]
public class FileAccessI implements Serializable{ z12c9k%s
i7RW8*
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 R Wd#)3
RandomAccessFile oSavedFile; J|Xu]fg0
long nPos; \B<A.,i4
.eSMI!Y=
nU6WT|
public FileAccessI() throws IOException <X{hW^??)
{ }?vc1%w
this("",0); NIQX?|;b{
} YyZ>w2_MTi
3X,SCG
=?, dX
public FileAccessI(String sName,long nPos) throws IOException ]DaC??%w
{ \~YyY'J
oSavedFile = new RandomAccessFile(sName,"rw"); G\S>H
this.nPos = nPos; xlH?J;$
oSavedFile.seek(nPos); q[}[w!to
} b)eKa40Z
A`D^}F6
rLfhm Ds%u
public synchronized int write(byte[] b,int nStart,int nLen) .$k2.-k
{ mR? } gR
int n = -1; V(Dn!Nz
try{ >;;tX3(
oSavedFile.write(b,nStart,nLen); _cW(R,i
n = nLen; 6.!3g(w
} 9b0M'x'W5
catch(IOException e) M_4:~&N$
{ $2M dxw5
e.printStackTrace (); WG_20JdJY
} N!`8-ap\^
}#rdMh
4G%!t`?q
return n; <Rl:=(]i~
} *FwHZZ~U
LQnkpy3A
SnhB$DG
} kUdl2["MZ
/cy'% .!
7sQw&yUL)
/* Vo\RtM/6{
**SiteInfoBean.java [;Q8xvVZ'
*/ kJJUu
package NetFox; G2nL#l~@)
xF+a.gAIb
sh6F-g
public class SiteInfoBean { 6PS #Zydb
^Fl6-|^~
Y]5\%JR
private String sSiteURL; //Site's URL *hHy>(*
private String sFilePath; //Saved File's Path l @hXQ/
private String sFileName; //Saved File's Name Dm=Em-ST6
private int nSplitter; //Count of Splited Downloading File _d$0(
P~)ndaQ
? 9.V@+i
public SiteInfoBean() ERW>G{+
{//nSplitter的缺省值为5 )TceNH
//default value of nSplitter is 5 G36}4
this("","","",5); N F[v/S
} OAc*W<Q0
b[^=GF>e
yn0OPjH
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) >b |TaQ
{ x9#>0 4s
sSiteURL= sURL; o@`& h} $
sFilePath = sPath; sOJH$G3O
sFileName = sName; w$9aTL7
this.nSplitter = nSpiltter; C^@.GA
7L[HtwI
nb:J"
} }57wE$9K
t5z6{`
sW~Z?PFP
public String getSSiteURL() !af35WF
{ qAsZ,ik
return sSiteURL; g1Q^x/
} OCzWP,
# E'g{.N
G 1{F_
public void setSSiteURL(String value) eH2.,wY1
{ rl^_RI
sSiteURL = value; J9oGwP
} #&G^%1!
b;&J2:`
#,O<E@E
public String getSFilePath() |X9YVZC
{ B.&ly/d
return sFilePath; oJK]oVX9i
} . `lcxC
p+ymtPF
[R j=k)aBm
public void setSFilePath(String value) ,UQ4`Mh^L
{ 0X\,!FL
sFilePath = value; +XU*NAD,!
} EA4aZ6%
,MwwA@,9-
JBdZ]
public String getSFileName() !!ZNemXct$
{ "k\W2,q[
return sFileName; }io9Hk>|
} R|h9ilc
lY_E=K]
*k'oP~:fT
public void setSFileName(String value) XpWqL9s_E
{ VAc-RaA
sFileName = value; CD(2A,u)/
} 6OMywGI[Z
$=n|MbFl
/Cr0jWu _
public int getNSplitter() j_SRCm~:
{ pi? q<p%
return nSplitter; ;$(a+?
} +bvY*^i
Q"CZ}B1<
MP?9k)f
public void setNSplitter(int nCount) \cvui^^n
{ @*L^Jgn
nSplitter = nCount; G*e/Ft.wf8
} +Ij>\;vM"
} ghJ81
uk_?2?>-5
BCF-lrZ&
/* aT"q}UTK
**Utility.java =-{+y(<"r
*/ v')Fq[H
package NetFox; $k*E^~qT
!1!;}uzt
]i\D*,FfU
public class Utility { I(/W+o
A\lnH5A
.Xh^L
public Utility() mgX0@#wFn
{ 0U ?1Yh7 m
4(2}O-~
p+#J;.
} +"Ek? )?
X1!m]s(I
//线程睡眠 Lie\3W
public static void sleep(int nSecond) +wwpaR`
{ =(K;z9OR
try{ tTe\#o`
Thread.sleep(nSecond); {w}PV5<
} \TkBV?W
catch(Exception e) ,g@U*06
{ %Y:'5\^lC
e.printStackTrace (); ~d?7\:n
} bSU9sg\
} /!oi`8D
KWCA9.w4q
//日志 o5mt7/5[i
public static void log(String sMsg) S%-L!V ,
{ 6cVaO@/(
System.err.println(sMsg); c^}gJ
} h"Yi'
j\f;zb?F
jY$Bns&.w
public static void log(int sMsg) ;$&&tEh)
{ ik_Ll|
System.err.println(sMsg); 724E(?>J
} }E[S%W[
} tx}{E<\>$
}:5r#Cd
&`Q0&8d5
/* DoX#+ 07u4
**TestMethod.java =et=X_3-
*/ ]zmY]5
package NetFox; G#@o6r
v)!Rir5
'h%)@q)J)
public class TestMethod { &!2 4l=!
ae{%* \J
0Q_AF`"
public TestMethod() #JYv1F
{ ///xx/weblogic60b2_win.exe %L}9nc%~eP
try{ [?)}0cd0
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #q9jFW8
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); zPWG^
SiteFileFetch fileFetch = new SiteFileFetch(bean); >1T=Aw2Z.
fileFetch.start(); <<6i6b
} 5'?K(Jdmp
catch(Exception e){e.printStackTrace ();} bT,]=h"0
U PGS
acdaDY
} M'$n".,p
WM*[+8h
eEb(TG~,Y
public static void main(String[] args) A&~G
{ i*#Gq6qZq
new TestMethod(); h35x'`g7+r
} 2Y\,[$z
} B<xBuW
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