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)); Mc$rsqDz
} E[4 vUnm-
for(int i=0;i<nEndPos.length-1;i++) *B9xL[}
{ GK[9IF#_>
nEndPos = nStartPos[i+1]; nq~fH(QY
} ixE w!t
nEndPos[nEndPos.length-1] = nFileLength; hTmJ ~m'J
} 6\`8b&'n
} 15yiDI o
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COmu.'%*
//启动子线程 B+Ft >
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Kf_xKW)^
for(int i=0;i<nStartPos.length;i++) 7PBE(d%m
{ \,r*-jr
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0j8`M"6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), afzx?ekdF
nStartPos,nEndPos,i); ?e,:x ]\L
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); #)]/wqPoW
fileSplitterFetch.start(); mIqm/5
} =E^/gc%X
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I5`>XfO)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Wh~,?}laj
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", lcgG5/82
nEndPos = " + nFileLength); 8si{|*;hL
// fileSplitterFetch[nPos.length-1].start(); VT=gb/W6)a
PsD)]V9%:
0rm(i*Q
//等待子线程结束 o[i*i<jv-
//int count = 0; 7AWq3i{
//是否结束while循环 =6'bGC%c
boolean breakWhile = false; P ?nk>
gsl_aW!
8Op^6rX4
while(!bStop) jzBW'8
{ _*b`;{3
write_nPos(); jicH94#(]
Utility.sleep(500); .GL@`7"
breakWhile = true; S?J(VJqE
`"<hO 'WU
lP*=4Jh
for(int i=0;i<nStartPos.length;i++) `AvK=]
{ G6G-qqXy6
if(!fileSplitterFetch.bDownOver) ]qu6/Z
{ 65*Hf3~~
breakWhile = false; w{So(AF
break; \sfc!5G
} '>n&3`r5
} hw*u.46
if(breakWhile) [Q J
break; zufsmY4P
h.KgHMV`
lNtxM"G&
//count++; 1i_%1Oip
//if(count>4) 3la`S$c
// siteStop(); K<`W>2"
} _Hfpizm
5`gVziS!S
j+{cc: h"X
System.err.println("文件下载结束！"); 7YK6e
} >]C/ Q6
catch(Exception e){e.printStackTrace ();} mg@Ol"2
} (@qS
AE~@F4MK
SJc~E$5<
//获得文件长度 !H{>c@i
public long getFileSize() mH4u@aQ}
{ `'k2gq&
int nFileLength = -1; ~(huUW
try{ >5"e<mwD7d
URL url = new URL(siteInfoBean.getSSiteURL()); >goHQ30:
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (E&M[hH+
httpConnection.setRequestProperty("User-Agent","NetFox"); ysl#Rwt/2
s S#/JLDx]
3}&3{kt
int responseCode=httpConnection.getResponseCode(); DHx&%]r;D
if(responseCode>=400) $!y^t$u$@
{ JYA>Q&
processErrorCode(responseCode); M_.Jmh<&&
return -2; //-2 represent access is error (2M00J-o
} ^cSfkBh
}#%YeCA?
-!O8V
String sHeader; z,7;+6*=L
@:#J^CsM+'
jm@M"b'{
for(int i=1;;i++) D!/ 4u0m
{ /h.{g0Xc
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); xpo^\E?2
//Utility.log(in.readLine()); #62ThH~
sHeader=httpConnection.getHeaderFieldKey(i); hsS&|7Pt
if(sHeader!=null) N:k>V4oE
{ tcsb]/my
if(sHeader.equals("Content-Length")) gsM^Pu09ud
{ |G$-5 7fk
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Dq$1 j%4Y
break; Y~A I2HS
} }1~9i'o%Z
} #N>66!/V
else "::2]3e
break; 6NhGTLI
} %dq%+yw{%m
} F;h^o!W7r
catch(IOException e){e.printStackTrace ();} B)1(
catch(Exception e){e.printStackTrace ();} K[0z$T\
D15-pz|Q
u a_w5o7
Utility.log(nFileLength); v1X[/\;U
T4"D&~3 3q
ztX$kX:_m
return nFileLength; ;v2eAe@7
} /F~/&p1<\k
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i20y\V os?
//保存下载信息（文件指针位置） knph549
private void write_nPos() K%mR=u#%&
{ SJMbYjn0J
try{ HiU)q
output = new DataOutputStream(new FileOutputStream(tmpFile)); ~9vK6;0
output.writeInt(nStartPos.length); ujmIS~"
for(int i=0;i<nStartPos.length;i++) j|K;Yi
{ qm:C1#<p
// output.writeLong(nPos); ~D4l64
output.writeLong(fileSplitterFetch.nStartPos); j4=iHnE;
output.writeLong(fileSplitterFetch.nEndPos); eI2HTFyT
} eA-oqolY
output.close(); $,U/,XA {E
} ,*d8T7T
catch(IOException e){e.printStackTrace ();} SlR//h
catch(Exception e){e.printStackTrace ();} ZAN~TG<n
} >(.|oT\Tb
=#y;J(>~|
PQSmBTs.
//读取保存的下载信息（文件指针位置） KA?%1s(kJ
private void read_nPos() sCrP+K0D
{ OW\vbWX
try{ 87+fd_G
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); =mZYBm,IQ
int nCount = input.readInt(); Y:,C_^$w;
nStartPos = new long[nCount]; #Pf<2S
nEndPos = new long[nCount]; <4vCx
for(int i=0;i<nStartPos.length;i++) jK*d
{ ~S;-sxoO0l
nStartPos = input.readLong(); Q>Z~={"
nEndPos = input.readLong(); gH'hA'
} jI*@&3
input.close(); wS#Uw_[
} 6fo"k+S
catch(IOException e){e.printStackTrace ();} w(S~}'Sg*P
catch(Exception e){e.printStackTrace ();} NQ 6oyg@&
} 1v`|mU}i,
E7? n'!=
5=|h~/.k
private void processErrorCode(int nErrorCode) 7I"~a<f0X`
{ 5o>`7(t`
System.err.println("Error Code : " + nErrorCode); rM A%By^L-
} [w@S/K[_|
GU2TQx{V
MQN~I^v3
//停止文件下载 |/n7(!7$[v
public void siteStop() ^tG,H@95
{ \X%FM"r
bStop = true; ``VE<:2+
for(int i=0;i<nStartPos.length;i++) i.)n#@M2
fileSplitterFetch.splitterStop(); t^YtP3`?b
jmaw-Rx
Jk&!(YK&
} pY )x&uM!
} SF,:jpt`Z+
//负责部分文件的抓取 X5[t6q!
**FileSplitterFetch.java {x,)OgK!{
*/ ?yq=c
package NetFox; Um4zI>
x}c
.-tR <{ g
import java.io.*; 2xO[ ?fR
import java.net.*; DH+kp$,}
zs I?X>4
(ub(0 h0j
public class FileSplitterFetch extends Thread { Il&7n_ H
dG5jhkPX
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String sURL; //File URL cRrJZ9
long nStartPos; //File Snippet Start Position M3@qhEf?vk
long nEndPos; //File Snippet End Position s<!G2~T
int nThreadID; //Thread's ID DAWF =p]
boolean bDownOver = false; //Downing is over /Z^a,%1
boolean bStop = false; //Stop identical L@AFt)U
FileAccessI fileAccessI = null; //File Access interface J.4U;A5
]9/A=p?J@
}l$zZ>.\H
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException r.#r!.6 q
{ r1%{\<
this.sURL = sURL; %?gG-R
this.nStartPos = nStart; a"U3h[;$y
this.nEndPos = nEnd; -sJD:G,%
nThreadID = id; q&v~9~^}d
fileAccessI = new FileAccessI(sName,nStartPos);//定位 !10/M
} rmkBp_i{|
K\U`gTGc
v8yCf7+"
public void run() {*GBUv5
{ v(.mM9>
while(nStartPos < nEndPos && !bStop) BX[IWP\%
{ PL$XXj>|:
8HBwcXYoHh
IP#vfM
try{ {q8|/{;
URL url = new URL(sURL); )?#K0o[<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); @hg[v`~
httpConnection.setRequestProperty("User-Agent","NetFox"); N^[ F+y
String sProperty = "bytes="+nStartPos+"-"; aQx6;PC
httpConnection.setRequestProperty("RANGE",sProperty); /Ls|'2J<$
Utility.log(sProperty); zu @|"f^`
zMP6hn
W1"NKg~4
InputStream input = httpConnection.getInputStream(); ff.k1%wr^
//logResponseHead(httpConnection); CS~onf<xz
=Vs?=|r
n8;L_43U
byte[] b = new byte[1024]; xk>cdgt
int nRead; dR\yRC]I
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) }a5TY("d9H
{ 3R%JmLM+R9
nStartPos += fileAccessI.write(b,0,nRead); gtMR/P:S
//if(nThreadID == 1) Fik;hB
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |wuTw|
} A)n_ST0
LZ_VLW9wE
,S`n?.&& 7
Utility.log("Thread " + nThreadID + " is over!"); 5O]tkHYR
bDownOver = true; U~ a\v8l~
//nPos = fileAccessI.write (b,0,nRead); unn2I|XH
} 8ly)G
catch(Exception e){e.printStackTrace ();} K(upzn*a
} us|Hb
} 1DcBF@3sWG
>^g2Tg:
QEt"T7a[/
//打印回应的头信息 (jU_lsG
public void logResponseHead(HttpURLConnection con) >>KI_$V
{ )GG9[%H!
for(int i=1;;i++) xgIb6<qwY
{ aIa<,
String header=con.getHeaderFieldKey(i); '12*'Q+{+
if(header!=null) RDDA^U7y#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); uNuFD|aQ.
Utility.log(header+" : "+con.getHeaderField(header)); T=-UcF
else +fboTsp% H
break; M}11 tUl
} |A*4Fuc&
} 7=?!B#hm!
G5U?]& I8
Ar>JQ@0
public void splitterStop() %zGv+H?
{ ~Oq _lM
bStop = true; y$-@|M$GG
} ?eX$Wc{
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\)uA:v
} 2=K|kp5
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-n|>U:
/* c$ib-
**FileAccess.java o[Qb/ 7
*//文件访问(定位，写) GP4!t~"1
package NetFox; 4bL *7bA
import java.io.*; S"G(_%
uQ_C<ii"W
%b*N.v1+
public class FileAccessI implements Serializable{ M-h+'G
LRu*%3xx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yKj}l,i~8
RandomAccessFile oSavedFile; +zche
long nPos; 1K/ :
1HNP@9ga
F!hjtIkPj
public FileAccessI() throws IOException #3_g8ni5X
{ 6:%lxG
this("",0); )ddJ\:
} R$l- 7YSt
bFN/{^SB
!YGHJwW:
public FileAccessI(String sName,long nPos) throws IOException N5zWeFq@6
{ up['<Kt+a
oSavedFile = new RandomAccessFile(sName,"rw"); L$O\fhO?
this.nPos = nPos; ^ICSh8C
oSavedFile.seek(nPos); ?+d{Rh)y
} G.L}VpopM
/# Jvt
ldp9+7n~
public synchronized int write(byte[] b,int nStart,int nLen) y[l{ UBue:
{ I>nYI|o1
int n = -1; Ek `bPQ5
try{ .GJbrz
oSavedFile.write(b,nStart,nLen); ly34aD/p~,
n = nLen; q 6UZ`9&z
} lbt8S.fx
catch(IOException e) D1-w>Y#
{ pm=O.)g4`
e.printStackTrace (); Ag\RLJ.KD
} RjviHd#DXn
oh$"?N7n1
:^`j:B
return n; n6Uh%rO7S|
} N{g7
,m`&J?
\i,H1a
} GFPrK9T
q['D?)sy
~cp=B>*(
/* *LBF+L^C%
**SiteInfoBean.java nkPlfH
*/ \9p.I?=
package NetFox; [I%eRo[
Jxe5y3* (
S[9b I&C
public class SiteInfoBean { 2"a%%fv
^kcuRJ0*$
8i;drvf
private String sSiteURL; //Site's URL {ST8'hY
private String sFilePath; //Saved File's Path ec#`9w$
private String sFileName; //Saved File's Name J&h59dm-
private int nSplitter; //Count of Splited Downloading File :9(kU
5s^vC2$)
9+m>|"F0
public SiteInfoBean() |7,$.MK-@
{//nSplitter的缺省值为5 uZ_?x~V/
//default value of nSplitter is 5 H74'I}
this("","","",5); }03?eWk/y
} <!G /&T
sdCG}..`
V}<<?_
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fFbJE]jW
{ P]}:E+E<.I
sSiteURL= sURL; 11QZ- ^
sFilePath = sPath; S9l po_!z
sFileName = sName; {}'Jr1
this.nSplitter = nSpiltter; YY tVp_)
r%=a:GdAg
AFsieJ
} 6@#=z
.yUD\ZGJu
Gl{'a1
public String getSSiteURL() 7\$}|b[9
{ /o$6"~t
return sSiteURL; g$)0E<
} Tg@G-6u0c
34)l3UI~
7`L]aRS[
public void setSSiteURL(String value) 0hkYexX73
{ ) xV>Va8)
sSiteURL = value; 9fbo
} n@kJ1ee'
h){#dU+&
@/As|)
public String getSFilePath() D.7cWR`Wp
{ B(71I;
return sFilePath; EqD@o
} "S{GjOlEDF
8TH;6-RT
dQH8s
public void setSFilePath(String value) {7IZN< e
{ {be|G^.c
sFilePath = value; A`vRUl,c=
} :SN?t
OBlQ
$M-"az]
public String getSFileName() rFC9y o
{ v%`k*n':
return sFileName; 4s>L]! W$8
} *}HDq(/>w
j1Sjw6}GCH
w"M!**bP
public void setSFileName(String value) 4M>]0%3.D
{ #>CWee;
sFileName = value; rjfWty%6pX
} >PdrLwKS
pkG8g5(w
)<'2 vpz
public int getNSplitter() 2^5RQl/
{ 33}p02#
return nSplitter; qixnaiZ
} _ !"[Zr
buKkm$@w
A;/,</
public void setNSplitter(int nCount) H,/=<Th;i
{ `7``1TL
nSplitter = nCount; _q-k1$o$
} 4yMi9Ri4H
} 5``usn/&Kj
5K|`RzZ`B$
5D^2 +`$/
/* d"ZsOq10D
**Utility.java ,HE{&p2y
*/ 0Iyb}
package NetFox; '|tmmoY6a:
Frx_aGLH1
8&x&Ou$("V
public class Utility { /^~)iTwH
y(C',Xn
44^jE{,9
public Utility() ] :](xW%
{ qw|B-lT{:
~:0U.v_V
*&_(kq z'1
} |U~\;m@
&u2m6 r>W
//线程睡眠 GIkVU6Q}
public static void sleep(int nSecond) '|%\QWuZ
{ u8x#XESR7
try{ yi-)4#YN
Thread.sleep(nSecond); "[_gRe*2
} l~1l~Gx_&n
catch(Exception e) =jG."o
{ )ZZ6 (O
e.printStackTrace (); \<}e?Yx%
} gZz5P>^
} mX@xV*
*L<<S=g$2
//日志 FYg{IKg
public static void log(String sMsg) /I`-
{ k1D|Cpnp
System.err.println(sMsg); VB+_ kR6Zv
} ?%>S5,f_
8js1m55KT
R C!~eJG!
public static void log(int sMsg) ]>+ teG:4
{ o8A(Cg}
System.err.println(sMsg); xiC.M6/
} u3 4.
} i Hcy,PBD
5cr\ JR
1R.6Xer
/* @zsqjm
**TestMethod.java _^0UK|[
*/ y&F&Z3t
package NetFox; PC?XE8o
*M~BN}.
;T!ZO@1X
public class TestMethod { Z7MGBwP(
sdQ"[`~2R
*APTgXYR
public TestMethod() SQG9m2
{ ///xx/weblogic60b2_win.exe qHYoQ.ke
try{ oHethk
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ) @f6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ir;az{T#U
SiteFileFetch fileFetch = new SiteFileFetch(bean); s<LYSrd
fileFetch.start(); (=Lx9-u
} 40;4=
catch(Exception e){e.printStackTrace ();} FCt %of#
EHq?yj;
>\1j`/ :ZI
} [@$t35t~
U,\t2z
$)jf
public static void main(String[] args) cD<5~`l
{ Xf|I=XK
new TestMethod(); _$gP-J
} S1*xM
} @$|bMH*1:
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