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)); 9w.ZXd
} u[6aSqwC|
for(int i=0;i<nEndPos.length-1;i++) l#&\,T
{ dmPAPCm%y
nEndPos = nStartPos[i+1]; z8<"
} \pVNJy$`<
nEndPos[nEndPos.length-1] = nFileLength; 4uE|$
} j7yUya&
} WSqo\]
6kHuKxY,
b8&z~'ieR
//启动子线程 >D_!d@Z
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6vf<lmN
for(int i=0;i<nStartPos.length;i++) ODKHI\U
{ ]ASTw(4
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Q.g44>
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Ntlbn&lc;D
nStartPos,nEndPos,i); O #5`mo
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d@ef+-
fileSplitterFetch.start(); uJU;C.LX
} o[aIQ|G
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U*\1d
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); g9AA)Ykp
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", d,E2l~s
nEndPos = " + nFileLength); 9a]JQ
// fileSplitterFetch[nPos.length-1].start(); ]SUW"5L-
/>O.U?
=8AL>:_
//等待子线程结束 Zb:S IJ
//int count = 0; 5`)[FCQ
//是否结束while循环 ld7B{ ?]
boolean breakWhile = false; HXgf=R/$
A'suZpL
VEx )
while(!bStop) ne# %Gr
{ j`QXl
write_nPos(); { {+:Vy
Utility.sleep(500); %<\tN^rP
breakWhile = true; !RwMUnp
#YK=e&da
h3V; J
for(int i=0;i<nStartPos.length;i++) I@ D<rjR
{ ]u47]L#
if(!fileSplitterFetch.bDownOver) dG)}H_
{ )JOo|pr-K
breakWhile = false; B3Ws)nF"
break; 4okZ
} <*z9:jzQ
} t:%u4\nZ;
if(breakWhile) TE-(Zil\
break; Q#pgl
n!L}4Nmp
bq z*90
//count++; UQq Qim
//if(count>4) y-_IMu.J`
// siteStop(); &"=<w
} +@MG$*}Oz
KQCF "
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System.err.println("文件下载结束！"); JPq' C$
} @!B%ynrG
catch(Exception e){e.printStackTrace ();} vlPViHF.
} te+r.(p
m'U>=<!D
K%YR; )5A
//获得文件长度 ese?;1r
public long getFileSize() ?-=<7 ~$
{ j=Z;M1
int nFileLength = -1; 89ab?H}/
try{ +m1*ou'K
URL url = new URL(siteInfoBean.getSSiteURL()); jR"ACup(
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]QKKtvN
httpConnection.setRequestProperty("User-Agent","NetFox"); u(g9-O
' [%?j?2r
|t_SN,)dd
int responseCode=httpConnection.getResponseCode(); !DXK\,;>
if(responseCode>=400) ap[Q'=A`
{ bEb+oRI
processErrorCode(responseCode); dQI6.$?
return -2; //-2 represent access is error s[}cj+0
} y~<_ux,
lGX8kAv?
S{UEV7d:n0
String sHeader; <,Fj}T-
dyt.(2
Xd'B0kQaT
for(int i=1;;i++) +[Q`I*C
{ 2Jqr"|sw
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); *u!l"0'\
//Utility.log(in.readLine()); gCM(h[7A
sHeader=httpConnection.getHeaderFieldKey(i); Q;=3vUN
if(sHeader!=null) a4eE/1
{ -o YJ&r
if(sHeader.equals("Content-Length")) rXVRX#Lh
{ ] jycg@=B
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }XfRKGQw
break; v+ "9&
} PGA `R
} }PzHtA,V
else nOK1Wc%/'
break; >H,PST
} #z9@x}p5g
} /\5u-o)
catch(IOException e){e.printStackTrace ();} c6LPqPcN
catch(Exception e){e.printStackTrace ();} VX e7b
:@J.!dokF
3.@ir"vy
Utility.log(nFileLength); 5>&C.+A 9
L%I8no-Q
^Kn:T`vB
return nFileLength; w s7LDY&(
} X,`e1nsR
_OJ19Ry
HQV#8G#B
//保存下载信息（文件指针位置） W"1=K]B
private void write_nPos() >{=~''d,w
{ :6W* ;<o
try{ k9iB-=X?4s
output = new DataOutputStream(new FileOutputStream(tmpFile)); E 7"`D\*
output.writeInt(nStartPos.length); FyA0"
for(int i=0;i<nStartPos.length;i++) d?4-"9Y
{ =7-@&S=?s
// output.writeLong(nPos); gU@BEn}
output.writeLong(fileSplitterFetch.nStartPos); _+. )8
output.writeLong(fileSplitterFetch.nEndPos); ;a`I8Fj
} w'<"5F`
output.close(); -qJO6OM
} hmJa1fw=
catch(IOException e){e.printStackTrace ();} AHn Yfxv_
catch(Exception e){e.printStackTrace ();} *w6(nG'M{
} +P;&/z8i*g
)%~<EJ*&Z
y\<\P8X
//读取保存的下载信息（文件指针位置） ~P!%i9e_
private void read_nPos() 1IWP~G
{ $ cYKVhf
try{ n!%'%%o2v
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %Su,
int nCount = input.readInt(); ,\D*=5
nStartPos = new long[nCount]; i>z {QE
nEndPos = new long[nCount]; fnn/akGKI
for(int i=0;i<nStartPos.length;i++) NSQ#\:3:S
{ a VIh|v
nStartPos = input.readLong(); "[\),7&03
nEndPos = input.readLong(); EGK7)O'W
} zC_@wMWB
input.close(); VU\{<j{
} BVv{:m{w
catch(IOException e){e.printStackTrace ();} 7kh(WtUz
catch(Exception e){e.printStackTrace ();} >d$Sh`a6
} n{xL1A=9
YY 8vhnw
nBGcf(BE.$
private void processErrorCode(int nErrorCode) a,KqTQB
{ {[[/*1r|
System.err.println("Error Code : " + nErrorCode); GJn ~x
} .X{U\{c|a
D@o8Gerq~
?a'P;&@7
//停止文件下载 9Vtn62+
public void siteStop() 4,?ZNyl
{ CL<m+dW%*
bStop = true; *&~wl(+O=
for(int i=0;i<nStartPos.length;i++) oE'Flc.
fileSplitterFetch.splitterStop(); "i~~Q'=7
e6uVUzP4
8 J;\Z
} qt4^e7o
} ;@V1*7y
//负责部分文件的抓取 `E-cf7%
**FileSplitterFetch.java Qs;MEt1
*/ 3Tz~DdB
package NetFox; E*{_=pX
L3y`*&e>
i=X B0-
import java.io.*; A!^gF~5
import java.net.*; #wfb-`,5&9
F]6$4o[
}+i~JK
public class FileSplitterFetch extends Thread { MNd[Xzm
wv&#lM(
(v1~p3H
String sURL; //File URL l[M?"<Ot;
long nStartPos; //File Snippet Start Position >PoVK{&y
long nEndPos; //File Snippet End Position %mMPALN]{
int nThreadID; //Thread's ID Kld#C51X f
boolean bDownOver = false; //Downing is over fm&pxQjg
boolean bStop = false; //Stop identical l|5;&(Y+s
FileAccessI fileAccessI = null; //File Access interface \I #}R4z
*1CZRfWI
gkL{]*9&%
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException W^N|+$g>H
{ ^=7XA894
this.sURL = sURL; !7jVKI80
this.nStartPos = nStart; QV9z81[
this.nEndPos = nEnd; CCU<t Q
nThreadID = id; tLo_lLn*~%
fileAccessI = new FileAccessI(sName,nStartPos);//定位 J0,;F9<C#X
} .lyK ,p
qotWWe#
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public void run() l&oc/$&|[
{ J3,m{%EtNM
while(nStartPos < nEndPos && !bStop) 2^4OaHY88
{ 9jW"83*5
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;cp,d~mrf
try{ [LDY;k~5+
URL url = new URL(sURL); 5:|=/X%#qp
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); "]ZDs^7
httpConnection.setRequestProperty("User-Agent","NetFox"); )Rr0f 8
String sProperty = "bytes="+nStartPos+"-"; tl+ 9SBl
httpConnection.setRequestProperty("RANGE",sProperty); ]8dzTEjk
Utility.log(sProperty); sX,S]:X
"ot#g"
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InputStream input = httpConnection.getInputStream(); OS sYmF
//logResponseHead(httpConnection); O8)N`#1>+
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#8@o%%Fd
byte[] b = new byte[1024]; y{Vh?Z<E
int nRead; 5dkXDta[G
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) B\Uocn
{ LZ<^b6Dxk
nStartPos += fileAccessI.write(b,0,nRead); }0~X)Vgm(
//if(nThreadID == 1) YuFR*W;$
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SaSj9\o
} dq^vK
tZan1C%p>
)SyU
Utility.log("Thread " + nThreadID + " is over!"); njckPpyb@
bDownOver = true; {.o@XP,.
//nPos = fileAccessI.write (b,0,nRead); z#^;'nnw
} _(F8}s
catch(Exception e){e.printStackTrace ();} 4}F~h
} =Hx]K8N)
} HMmB90P`
6|Xe ],u
.X34[AXd
//打印回应的头信息 JsHD3
public void logResponseHead(HttpURLConnection con) )W*A[c 2
{ h&2l0|8k
for(int i=1;;i++) Cf>(,rt};
{ +F+M[ef<ws
String header=con.getHeaderFieldKey(i); odWK\e
if(header!=null) _BZ6Ws$C2
//responseHeaders.put(header,httpConnection.getHeaderField(header)); f"SK3hI$p
Utility.log(header+" : "+con.getHeaderField(header)); uYC1}Y5N
else pT/z`o$#V
break; AK(x;4
} N5.B"l
} CD[}|N
%S/?Ci
gUY~ l= c
public void splitterStop() a'(B}B=h
{ '^M.;Giz
bStop = true; mM.YZUX
} ^09-SUl^
U1O8u-X
`T{'ufI4B
} 0ZJj5<U
;Vpp1mk|
=YY 7V!
/* %~L"TK`?
**FileAccess.java >:HmIW0PLe
*//文件访问(定位，写) b8E7/~<z3
package NetFox; )+|Y;zC9
import java.io.*; ih-J{1
}$i/4?dYsQ
+QNsI2t;r
public class FileAccessI implements Serializable{ )]kxLf#
rn/~W[
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 l=ZD&uK
RandomAccessFile oSavedFile; ]kd:p*U6P
long nPos; ;8a9S0eS
<~P!yLr
R3%%;`c=
public FileAccessI() throws IOException N'i)s{'
{ Bj<s!}i{[
this("",0); %SuELm
} _s*p$/V\
sNM ]bei
Ft38)T"2R\
public FileAccessI(String sName,long nPos) throws IOException Tl2(%qB
{ <Zvvx
oSavedFile = new RandomAccessFile(sName,"rw"); QiK-|hFj
this.nPos = nPos; X9ZHYlr+Q
oSavedFile.seek(nPos); '$),i>6gJ
} 7ug"SV6Hb
vn!5@""T
3?&v:H
public synchronized int write(byte[] b,int nStart,int nLen) `][vaLd`Q
{ 7Mk>`4D'c
int n = -1; &>&6OV]P'
try{ `mA;1S
oSavedFile.write(b,nStart,nLen); *<X1M~p$
n = nLen; (cyvE}g
} QO^V@"N
catch(IOException e) g9fYt&
{ [$;cjys
e.printStackTrace (); =fJU+N+<
} >]8(3&zd
b.v +5=)B
e^oGiL~
return n; k%X $@NP
} V:>r6
>I/@GX/
.$7RF!p
} ptrwZ8'
_VVq&t}
qS9<_if2
/* 1DcX$b
**SiteInfoBean.java OTE,OCB[
*/ '%wSs,HD
package NetFox; 0|.jIix;
qajZ~oB{
c BZ,"kp-
public class SiteInfoBean { 9cHo~F|ur
l5.k2{'
3UaW+@
private String sSiteURL; //Site's URL 1ANFhl(l
private String sFilePath; //Saved File's Path wN58uV '
private String sFileName; //Saved File's Name ^C1LQZ
private int nSplitter; //Count of Splited Downloading File 1Y*k"[?dW
!#:5^":;
:L@n(buRN
public SiteInfoBean() +<.o,3
{//nSplitter的缺省值为5 r7oFG!.?
//default value of nSplitter is 5 ?'Hd0)yZ
this("","","",5); yvj/u c
} ]XbMqHGS
,h*N9}xYTi
iiQ q112`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 7P<f(@0h$E
{ q)L4*O
sSiteURL= sURL; '~Cn+xf4]
sFilePath = sPath; }oA>0Nw$K
sFileName = sName; Jw8?o/1D@
this.nSplitter = nSpiltter; J@2wPKh?Yp
@fYVlHT%E
'/NpmNY:L
} [K$5Rm5
2H}y1bkW
Vx2/^MiXy
public String getSSiteURL() ;b*qunJ3L
{ &>C+5`bg
return sSiteURL; 5{k,/Z[L
} xi(1H1KN5B
Fz';H
vReX7
public void setSSiteURL(String value) bf0,3~G,P
{ 't}\U&L.{
sSiteURL = value; Y&j`HO8f
} R%RxF=@
Ao8ua|:
)f|`mM4DW!
public String getSFilePath() '"E!av>
{ I51]+gEN
return sFilePath; I2WP/
} tRJ5IX##L
=DJ:LmK
fMg9h9U
public void setSFilePath(String value) H^*AaA9-
{ (O4oIU
sFilePath = value; Hs'~)T
} BP@tI|
` = O
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public String getSFileName() FHQ`T\fC$@
{ 88v8lt;R
return sFileName; 9GH5
} a%B&F|u
5m0\ls\
m6mGcbpn
public void setSFileName(String value) +FqD.=8
{ f(w>(1&/B
sFileName = value; qisvGHo
} (l^7EpNs
"ktuq\a@
[w'Q9\,p
public int getNSplitter() iVn4eLK^v
{ W+!UVUpW
return nSplitter; +Pb:<WT}%
} ,~naKd.ZY
bPxL+ +
BA:x*(%~
public void setNSplitter(int nCount) H_$?b
{ #j~FlY5
nSplitter = nCount; =WT$\KYGv
} c EYHB1*cT
} \uOM,98xS
*uyP+f2O
!6'N-b1
/* S{;Pga*Px
**Utility.java ZX:rqc
*/ d#0:U Y%~
package NetFox; 4tZ*%!I'
?"9h-g3`x}
am]M2+,2Ip
public class Utility { "5V;~}=S
P0.cF]<m
^<OYW|q?\r
public Utility() xc#t8`
{ JLE&nbKS
{oqbV#/&
SUUNC06V
} :Ph>\aG
}(t`s
//线程睡眠 mF;mJq<d
public static void sleep(int nSecond) JI-i7P
{ cuQ!"iH
try{ Z&n[6aV'F
Thread.sleep(nSecond); d.vNiq,`
} }d?;kt
catch(Exception e) :0l+x0l}
{ juOStTq<
e.printStackTrace (); @-)?uYw:r
} >)ekb7
} B(;MI`
py'vD3Q
//日志 3@V?L:J
public static void log(String sMsg) f#!+l1GV
{ l/G+Xj4M
System.err.println(sMsg); x 7by|G(
} H[~ D]RG}'
&THtQ1D
C(XV YND3
public static void log(int sMsg) uB I/3aQ
{ _X4Y1zh
System.err.println(sMsg); 'v]0;~\mp>
} {6ZSf[Y6B
} 1VgGF^cYR
WoZU} T-
E#KZZ lbx
/* 7\ _MA!:<
**TestMethod.java oK\zyNK
*/ G+<XYkz*
package NetFox; NuQ!huh
+LRKS
dun`/QKV
public class TestMethod { ;mU;+~YE
sGu.G
C1D:Xi-
public TestMethod() Lm4`O%
{ ///xx/weblogic60b2_win.exe f`hZb
try{ 3*h"B$g!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); TTVmm{6
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); sjyr9AF
SiteFileFetch fileFetch = new SiteFileFetch(bean); EQ$k^Y8 "
fileFetch.start(); R0RxcBtG
} 8 MO-QO
catch(Exception e){e.printStackTrace ();} x &R9m,
OE@[a
>Q/;0>V
} Ur])*#
'OA*aQ=K
ZHNL~=r}
public static void main(String[] args) gQPw+0w
{ `D77CC]vU
new TestMethod(); ef`_ n+`
} ,\6Vb*G|E>
} J#$U<`j*G
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