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)); c6h+8QS
} &#gh :5
for(int i=0;i<nEndPos.length-1;i++) <%rm?;PBl
{ %3"U|Za+
nEndPos = nStartPos[i+1]; WB<MU:.Vc
} c9c3o{(6Y
nEndPos[nEndPos.length-1] = nFileLength; \IudS{ .?;
} ukc 7Z OQ
} QP%Hwt]+
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//启动子线程 BSJS4+,E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; kCoE;)y$
for(int i=0;i<nStartPos.length;i++) fOdqr
{ W2zG"Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3c(mZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), X=lsuKREZ
nStartPos,nEndPos,i); ._<, Eodv
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6X?:mn'%QF
fileSplitterFetch.start(); jt9- v-
} :xbj& l
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), i:jB
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); SyT{k\[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", kt\,$.v8
nEndPos = " + nFileLength); 4i}nk T
// fileSplitterFetch[nPos.length-1].start(); euRKYGW
YK$[)x\S
.n4{xQo,EJ
//等待子线程结束 r ?<kWR?w
//int count = 0; [u^ fy<jdp
//是否结束while循环 TA:uB[Ji
boolean breakWhile = false; gu~R4@3
AkdO:hVtG
F7nwVDc*
while(!bStop) C]l)Pz$
{ |!7leL
write_nPos(); )PYh./_2
Utility.sleep(500); ~x+'-2A46
breakWhile = true; .O(9\3q\
8bs'Ek{'o
?z6K/'?
for(int i=0;i<nStartPos.length;i++) KIR3m )
{ >&R@L KP
if(!fileSplitterFetch.bDownOver) J7%rPJ
{ \/gf_R_GN
breakWhile = false; j6$@vA)
break; #w\x-i|
} t%5bDdo
} *O@Zn
if(breakWhile) =h +SZXe<r
break; UJ%.KU%Q}
YWDgRb
A #m_w*
//count++; W&D{0i`y
//if(count>4) L;L_$hu)
// siteStop(); {D|ST2:E
} `.3.n8V
.f. tPm
"xHK*
System.err.println("文件下载结束！"); *n# =3D
} /YU8L
catch(Exception e){e.printStackTrace ();} #f_'&m
} bwP@}(K
v*.iNA;&i
+Zr~mwM=x
//获得文件长度 l,(:~KH|
public long getFileSize() .3n\~Sn
{ ips)-1
int nFileLength = -1; #Dz"g_d
try{ 9%3+\[s1
URL url = new URL(siteInfoBean.getSSiteURL()); f#!nj]}#
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); %hZX XpuO
httpConnection.setRequestProperty("User-Agent","NetFox"); UWS 91GN@
+j+ v(-
Jg{K!P|i
int responseCode=httpConnection.getResponseCode(); +F-Y^):
if(responseCode>=400) +ug/%Iay{k
{ GBR$k P
processErrorCode(responseCode); O{7#Xj :_
return -2; //-2 represent access is error iyr8*L\
} 1=sL[I7<
-b8SaLak
.V0fbHYTJ
String sHeader; 3B,dL|q(@J
F`(;@LO
AW|SD
for(int i=1;;i++) ,WnZ^R/n
{ jTV4iX
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); #*"V'dj;e
//Utility.log(in.readLine()); -a~n_Z>_
sHeader=httpConnection.getHeaderFieldKey(i); V6((5o#
if(sHeader!=null) ^J^FGo|M
{ kjdIk9 Y
if(sHeader.equals("Content-Length")) )8}k.t>'s
{ KC2Z@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C\Yf]J
break; `nEqw/I
} j;D$qd'J
} n6Uf>5
else Ars*H,9>e
break; 0L#i c61U
} /dvronG
} rLmc(-q
catch(IOException e){e.printStackTrace ();} #6[F&
catch(Exception e){e.printStackTrace ();} F9%+7Op^
V\r{6-%XiW
`Je1$)%
Utility.log(nFileLength); D/4]r@M2c
NYG!\u\Rm
<Uf`'X\e6
return nFileLength; Lw(tO0b2H
} 1|H4]!7kE
o~"Y_dLsW
ru`U/6n
//保存下载信息（文件指针位置） 83'+q((<
private void write_nPos() O#O"]A
{ 9(z) ^G
try{ 1x\k:2U
output = new DataOutputStream(new FileOutputStream(tmpFile)); s] ;P<
output.writeInt(nStartPos.length); 8+".r2*_iO
for(int i=0;i<nStartPos.length;i++) \*b .f
{ S&]r6ss
// output.writeLong(nPos); t#y,9>6
output.writeLong(fileSplitterFetch.nStartPos); _j0xL{&&
output.writeLong(fileSplitterFetch.nEndPos); xFM^-`7
} 34k>O
output.close(); *vIP\NL?H
} %N(>B_t\
catch(IOException e){e.printStackTrace ();} $Zw+"AA
catch(Exception e){e.printStackTrace ();} ~!g2+^G7+P
} +_bxza(ma{
4(oU88z
{[Y7h}7
//读取保存的下载信息（文件指针位置） "%a<+D
private void read_nPos() En\q. 3 5
{ zks7wt]A
try{ 7gB?rJHV,
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (#O"
int nCount = input.readInt(); $_TS]~y4}
nStartPos = new long[nCount]; 6J}Yr5oD
nEndPos = new long[nCount]; /N<aN9Z<x,
for(int i=0;i<nStartPos.length;i++) In1n.oRFn^
{ ANM=:EtP
nStartPos = input.readLong(); XOI"BLd
nEndPos = input.readLong(); UpE+WzY
} /^\E:(RH
input.close(); wF%RM$
} yZgWFf.X
catch(IOException e){e.printStackTrace ();} V rx,'/IS8
catch(Exception e){e.printStackTrace ();} _`^AgRE
} Tbv w?3
Umzb
zn&ZXFgN
private void processErrorCode(int nErrorCode) f8N*[by
{ (S+/e5c)
System.err.println("Error Code : " + nErrorCode); ^ +@OiL>&i
} )1Y?S;
P2aFn=f
@H4]Gp ]
//停止文件下载 ;s3\Z^h4kd
public void siteStop() i\b^}m8c.N
{ [+R_3'aK
bStop = true; ZS(%!+M
for(int i=0;i<nStartPos.length;i++) dW!El^w}
fileSplitterFetch.splitterStop(); zaLPPm&f
_xm<zy{`S
d4^x,hzV
} Qox/abC h
} ?a% F3B
//负责部分文件的抓取 9s[
**FileSplitterFetch.java NQZ /E )f
*/ )`'a1y|
package NetFox; $%"hhju
UQ;2g\([
-C~zvP;a
import java.io.*; (GpP=lSSeY
import java.net.*; RN[x\",
(?^F }]
^gp]tAf
public class FileSplitterFetch extends Thread { )8#-IXxp
x7<l*WQ
phf{b+'#X
String sURL; //File URL >4kQ9lXL
long nStartPos; //File Snippet Start Position )uo".n|n~B
long nEndPos; //File Snippet End Position b1i~F45h
int nThreadID; //Thread's ID R13k2jLSQ
boolean bDownOver = false; //Downing is over %k['<BYG<
boolean bStop = false; //Stop identical H'/V<%
FileAccessI fileAccessI = null; //File Access interface z;?jKE p
KGo^>us
>]gB@tn[
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ftPhE)i
{ xZ`vcS(
this.sURL = sURL; MnF|'t
this.nStartPos = nStart; %5KK#w "
this.nEndPos = nEnd; j?]+~
nThreadID = id; ~uZ9%UB_m
fileAccessI = new FileAccessI(sName,nStartPos);//定位 RfD#/G3|
} .|07IH/Di{
{Ke IYjE
@}!?}QU
public void run() !]A/ID0K
{ `fX\pOk~e
while(nStartPos < nEndPos && !bStop) W=293mME
{ BxlhCu
jCNR63/
nXb_\9E
try{ AI{0;0
URL url = new URL(sURL); !.O[@A\.-
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U"Bge\6x=
httpConnection.setRequestProperty("User-Agent","NetFox"); b`S9#`
String sProperty = "bytes="+nStartPos+"-"; v*JKLA
httpConnection.setRequestProperty("RANGE",sProperty); V?x&\<;,
Utility.log(sProperty); %P<fz1
G"u4]!$/
mr#.uhd.z
InputStream input = httpConnection.getInputStream(); cyHbAtl
//logResponseHead(httpConnection); aCQ[Uc<B:
|r;>2b/ x
p=x&X~
byte[] b = new byte[1024]; 1'TS!/ll];
int nRead; KV&6v`K/N
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tCR~z1
{ `}sFT:1&
nStartPos += fileAccessI.write(b,0,nRead); ,d_rK\J
//if(nThreadID == 1) gjnEN1T22
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xnWezO_
} [`tNa Vg
;WYzU`<g
_G<Wq`0w)
Utility.log("Thread " + nThreadID + " is over!"); lcReRcjm
bDownOver = true; 2MYez>D
//nPos = fileAccessI.write (b,0,nRead); \?8q&o1=]
} ls9Y?
catch(Exception e){e.printStackTrace ();} "ixea- 2
} DyZ6&*s$
} +CSR!
zn^ G V
/.A"HGAk
//打印回应的头信息 !e |Bi{
public void logResponseHead(HttpURLConnection con) W}zq9|p
{ UEYJd&n0CB
for(int i=1;;i++) HP<a'|r
{ u`(yT<>H
String header=con.getHeaderFieldKey(i); !lsa5w{
if(header!=null) a[}?!G-Wt|
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $1zWQJd[-
Utility.log(header+" : "+con.getHeaderField(header)); upeioC q
else v6L]3O1
break; >nvK{6xR:
} *(]ZdB_2
} B^R44j]3"
Z:x`][vg
6jm/y@|F!
public void splitterStop() P;'ZdZ(SLu
{ tBl(E
bStop = true; q%vel.L]%
} SsfC m C
z_{_wAuY
JlRNJ#h>
} @uQ *$
Wy/h"R\=
c_.Fe'E
/* \ZE=WvnhZ
**FileAccess.java Q~' \oWz
*//文件访问(定位，写) Pl`Nniy
package NetFox; H}CmSo8&
import java.io.*; MTNC{:Q
@" umY-1f
n3-VqYUP
public class FileAccessI implements Serializable{ 4)'U!jSb
ZYt<O
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 %yl17:h#
RandomAccessFile oSavedFile; qFq$a9w|@
long nPos; >XM]UdP
*{Z=)k%
d 792#Dc
public FileAccessI() throws IOException ub`zS-vb
{ /J&DYxl":
this("",0); vr2PCG[~
} Y ZuA"l Y
fYh<S
L$kB(Brw
public FileAccessI(String sName,long nPos) throws IOException @A*>lUo
{ $P%cdJT0
oSavedFile = new RandomAccessFile(sName,"rw"); )1HWD]>4
this.nPos = nPos; 0?gHRdU"
oSavedFile.seek(nPos); g+<[1;[-
} =1,1}OucP
apfr>L3
%*Uc,V
public synchronized int write(byte[] b,int nStart,int nLen) s2 :Vm\
{ <l5m\A
int n = -1; GCfVH?Vx
try{ <dr2 bz
oSavedFile.write(b,nStart,nLen); ReA-.j_2@
n = nLen; M:iH7K
} 6qT-
catch(IOException e) QgQ$>
{ RU~ku{8?
e.printStackTrace (); ;ny9q
} MOnTp8
W}MN-0
O7uCTB+
return n; 9 Qa_3+.B
} Z,Us<du
\4C[<Gbx$(
g%!U7CM6h
} 8Gnf_lkI
lmD[Cn
:Q@/F;Z?
/* t4/ye>P &
**SiteInfoBean.java cF8X
*/ FoH1O+e
package NetFox; x-%RRm<V
%b4tyX:N0
%d(= >
public class SiteInfoBean { /7:+.#Ag`
5s`r&2 w
.kPNWNrw
private String sSiteURL; //Site's URL 2l^_OrE!
private String sFilePath; //Saved File's Path 5I^;v;F
private String sFileName; //Saved File's Name u'>94Gm}
private int nSplitter; //Count of Splited Downloading File U"+W)rUd
9:-7.^`P
" r o'?
public SiteInfoBean() 7}6CUo
{//nSplitter的缺省值为5 0< vJ*z|_
//default value of nSplitter is 5 : MjDcI~
this("","","",5); _ezRE"F5
} IM/xBP
&r4|WM/ec
GQ7uxdqWBQ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ^7YNM<_%@
{ "`4ky]
sSiteURL= sURL; vO~Tx
sFilePath = sPath; ,p#B5Dif/
sFileName = sName; :/$WeAg
this.nSplitter = nSpiltter; T]-MrnO
Y7r;}^+WY
n-l_PhPQ`
} %]DA4W
/(51\RYkir
y#iz$lX R
public String getSSiteURL() sVw:d_ E
{ Mh5> hD
return sSiteURL; p'2IlQ\
} sg2%BkTI
a{hc{
lMvOYv
public void setSSiteURL(String value) 2[qfF6FHA
{ !W@mW 5J|
sSiteURL = value; ;..z)OP_
} n{sk
6Jb0MX"AVr
oYZ 4F
public String getSFilePath() ~a`[p\
{ *S:~U
return sFilePath; f?)7MR=
} PD.$a-t
7`;sX?R
{eaR,d~X
public void setSFilePath(String value) [=q/f2_1.
{ ^?+[yvq
sFilePath = value; xS/W}-dPv
} KxX[8
n*wQgC'vw
C:t>u..
public String getSFileName() m.Zy$SDj(
{ kWZY+jyt P
return sFileName; ?I[8rzBWU
} )/;+aDk
P>X[}
U`qC.s(L
public void setSFileName(String value) znsQ/[
{ b},2A'X
sFileName = value; JfN '11,$
} $lf/Mg_H
H@1'El\9
=6Ok4Z
public int getNSplitter() /GO-
{ H%vfRl3rB
return nSplitter; 8>eYM
} .t1:;H b
>fXtu:C-!J
1DB{"8ov
public void setNSplitter(int nCount) DlUKhbo$g
{ spfW)v/T!
nSplitter = nCount; =m2_:&@0x
} ~-A"j\gi"
} e^O:I
{O2=K#J
&<e18L7a
/* 2@ZVEN
**Utility.java (Ut8pa+yX
*/ a*5KUj6/TL
package NetFox; (&SU)Uvu
S=r0tao,!v
-13}]Gls7Q
public class Utility { + kKanm[!v
<(jk}wa<
w&L~+Z<
public Utility() Ih:Q}V#6
{ \PxT47[@e
~6i'V?>
6U !P8q
} EU[eG^/0@
d78 [(;
//线程睡眠 cOV9g)7^O
public static void sleep(int nSecond) IADHe\.
{ h_(M#gG
try{ e El)wZ,A
Thread.sleep(nSecond); (U&
} /X_L>or
catch(Exception e) E_=F'sP?
{ T>asH
e.printStackTrace (); J1}\H$*X
} 32 i6j
} ,5$G0
<Ja&z M
//日志 ~QbHp|g
public static void log(String sMsg) ,7j8+p|},
{ a5#G48'X
System.err.println(sMsg); !=:>yWQ
} \eKXsO"d
^nPy(Q0
{C5:as
public static void log(int sMsg) M3-lL;!n
{ by>%}#M
System.err.println(sMsg); ;=,-C;`
} Cw(e7K7&
} ch8VJ^%Ra1
xZ {6!=4!
vSnVq>-q&
/* .5Y{Yme
**TestMethod.java }9\_s*
*/ <=n;5hv:
package NetFox; ;9j ]P56
s-rc0:I
@}4>:\es
public class TestMethod { ^}~Q(ji7
@HbRfD/!
<}WSYK,zUY
public TestMethod() {nmu(EP
{ ///xx/weblogic60b2_win.exe !d()'N
try{ GG>53}7{
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); "~ID.G|<
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /}@F q
SiteFileFetch fileFetch = new SiteFileFetch(bean); >;Hx<FKxP
fileFetch.start(); 6ZIPe~`
} %q|*}l
catch(Exception e){e.printStackTrace ();} x,^-a
n@+?tYk*e
4|_xz;i
} y?UJ<QAi
$EY[CA E
lknj/i5L
public static void main(String[] args) oA5Qk3b:
{ Cl3vp_
new TestMethod(); Y[L,rc/j
} Jy:*GW6
} E&J<qTH9
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