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)); =fO5cA6Z
} PEW=@xj2y
for(int i=0;i<nEndPos.length-1;i++) n\^Tq<] a
{ xo7Kn+ Kl
nEndPos = nStartPos[i+1]; /JWGifH
} {o.FlX
nEndPos[nEndPos.length-1] = nFileLength; 4#:W.]U8
} %>g3~yl
} &2{tF
i}B2R$Z3
*U P@9D
//启动子线程 v#U"pn|M
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N _86t
for(int i=0;i<nStartPos.length;i++) {/ BT9|LI
{ Yq%9M=#k
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K|:@Z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), gk0(ANx
nStartPos,nEndPos,i); V4KMOYqm
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {M^3m5.^
fileSplitterFetch.start(); F!]lU`z)=
} 2AO~HxF
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZHm7Isa1
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); VB,?Mo}R
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", )'6DNa[y
nEndPos = " + nFileLength); g.zEn/SM
// fileSplitterFetch[nPos.length-1].start(); =9fajRFTt
A^y|J`k|
<U!`J[n%
//等待子线程结束 tX> G,hw
//int count = 0; ;;:-l99
//是否结束while循环 ,I%g|'2
boolean breakWhile = false; 93` AWg/T
2gCX}4^3b
RF%KA[Dj
while(!bStop) '>' wK.
{ WYEKf9}
write_nPos(); TwVlg;
Utility.sleep(500); urMG*7i <c
breakWhile = true; to=y#$_
Q=/</|
bqnNLs<N
for(int i=0;i<nStartPos.length;i++) Ns7(j-
{ oBzfbg8p
if(!fileSplitterFetch.bDownOver) +KvU$9Ad>
{ 2E)wpgUc?e
breakWhile = false; n1VaLD
break; nysUZB
} O"c;|zCc>
} b;cdIl!3
if(breakWhile) Z`KC%!8K
break; 3 %|86:*
&'}RrW-s
PEuIWXr
//count++; .tzG_
//if(count>4) o8-^cP1
// siteStop(); @]-jl}:]
} lJis~JLd`
79xx2
Ft;^g3N
System.err.println("文件下载结束！"); L&%s[
} 2|}+T6_q
catch(Exception e){e.printStackTrace ();} !WpBfd>v.I
} A#95&kJpy
}9W4"e2)
w6W}"Uw
//获得文件长度 (KF=On;=Y
public long getFileSize() Bb}fj28
{ 6Qy@UfB
int nFileLength = -1; kAC&S!n
try{ k+8q{5>A<
URL url = new URL(siteInfoBean.getSSiteURL()); 6DuEL=C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); jhg;%+KB
httpConnection.setRequestProperty("User-Agent","NetFox"); U}PiY"S<
,}))u0q+:
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int responseCode=httpConnection.getResponseCode(); [ zEUH:9D
if(responseCode>=400) dRaNzK)M
{ @Q/-s9b
processErrorCode(responseCode); L W;heO"
return -2; //-2 represent access is error >TP7 }u|
} 13+<Q \
H.WE6
:pF_GkG
String sHeader; q-`RI*1]
Cz W:L&t
.p=sBLp8
for(int i=1;;i++) DF g,Xa#
{ r} P<iX
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Ga^Zb^y
//Utility.log(in.readLine()); \T\b NbPn
sHeader=httpConnection.getHeaderFieldKey(i); "F}'~HWZp
if(sHeader!=null) Ik[s
{ zOSs[[
if(sHeader.equals("Content-Length")) .(X lg-H,
{ Pf$pt
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $F/EJ>
break; HoLv`JA
} 3 AHY|
} e{A9r@p!
else X!j{o
break; v|ck>_" .
} 7-~Q5Kr.
} $&=p+
catch(IOException e){e.printStackTrace ();} &%2*Wu;
catch(Exception e){e.printStackTrace ();} ;=9 >MS}
H%1$,]F
+hRmO
Utility.log(nFileLength); 2TES>}
~+H" -+
* FeQ*`r
return nFileLength; "GQl~
} 6MG9a>=
jV/CQM5a+
k;EPpr-{
//保存下载信息（文件指针位置） ?|1Mv1C?
private void write_nPos() JI/_ce
{ j6,ZEm
try{ +'G0{;b
output = new DataOutputStream(new FileOutputStream(tmpFile)); Qe'g3z>
output.writeInt(nStartPos.length); D-U<u@A4
for(int i=0;i<nStartPos.length;i++) /?6gdN
{ &(a(W22O
// output.writeLong(nPos); $3d}"D
output.writeLong(fileSplitterFetch.nStartPos); aP&D9%5
output.writeLong(fileSplitterFetch.nEndPos); @f!AkzI
} (5<^p&
output.close(); tQ~WEC
} W0zbxJKjd
catch(IOException e){e.printStackTrace ();} d vOJW".
catch(Exception e){e.printStackTrace ();} D\~e&0*
} o+?rI p
kJ(A,s|
}sxn72,
//读取保存的下载信息（文件指针位置） Vh<A2u3&
private void read_nPos() <8#ObdY!
{ `*\{.;,]#
try{ U,lJ"$'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); j}+5vB|0
int nCount = input.readInt(); L fl-!1
nStartPos = new long[nCount]; cE{ =(OQ
nEndPos = new long[nCount]; Sg] J7;]
for(int i=0;i<nStartPos.length;i++) ~"!a9GZ
{ &kQ!KA28
nStartPos = input.readLong(); DJQglt}~
nEndPos = input.readLong(); JeY'8B
} M8@_Uj
input.close(); cgj.e
} ^+R:MBK
catch(IOException e){e.printStackTrace ();} i_F$&?)
catch(Exception e){e.printStackTrace ();} }~o ikN:
} QMk+RM8U
(_9|w|(
^ft]b2i
private void processErrorCode(int nErrorCode) \,sg)^w@
{ C;a@Jjor'
System.err.println("Error Code : " + nErrorCode); LQ-6vrbs
} 8,o17}NY,
idJh^YD
g-yi xU
//停止文件下载 Y5-kj,CB
public void siteStop() gvnj&h.GV
{ o6?l/nJ
bStop = true; .yVnw^gu
for(int i=0;i<nStartPos.length;i++) `W[+%b
fileSplitterFetch.splitterStop(); 9.0WKcwg
ZM~`Gd9K0E
1.SkIu%
} %{STz
} ;o$;Z4:.D
//负责部分文件的抓取 u fw cF*
**FileSplitterFetch.java 8mgQu]>
*/ >IR$e=5$
package NetFox; fQQ|gwVki
*=vlqpG
)o8g=7Jm
import java.io.*; W@B7yP7Rz
import java.net.*; PZ34*q
3C"_$?y"
B <+K<,S
public class FileSplitterFetch extends Thread { 0yHjrxc$
cw+g z!!
g2'x#%ET
String sURL; //File URL +{6`F1MO
long nStartPos; //File Snippet Start Position M7VID6J.
long nEndPos; //File Snippet End Position \|Qb[{<:,
int nThreadID; //Thread's ID /{DaPqRa
boolean bDownOver = false; //Downing is over z{6YC~
boolean bStop = false; //Stop identical M5Wl3tZL
FileAccessI fileAccessI = null; //File Access interface b5Q8pWZg,
d_iY&-gq/
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Wy(pLBmb
{ 4zzlazU
this.sURL = sURL; E|,30Z+
this.nStartPos = nStart; 1uC;$Aj6:
this.nEndPos = nEnd; <Cr8V'c
nThreadID = id; }Eb]9c\
fileAccessI = new FileAccessI(sName,nStartPos);//定位 <p)Z/
} nFj-<!
#Jv43L H
zS?n>ElI
public void run() (h|ch#
{ Q^|6J#o[9
while(nStartPos < nEndPos && !bStop) YJc%h@_=]
{ KJ pj
|f3U%2@
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try{ shy
URL url = new URL(sURL); >"bnpYSe
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); e^Aa!
httpConnection.setRequestProperty("User-Agent","NetFox"); w`0)x5 TGR
String sProperty = "bytes="+nStartPos+"-"; ]DU61Z"v?b
httpConnection.setRequestProperty("RANGE",sProperty); }z?xGW/k
Utility.log(sProperty); 8Yxhd .
&!6DC5
T|!D>l'
InputStream input = httpConnection.getInputStream(); Y!;gQeC
//logResponseHead(httpConnection); 4XD)E&
.`mtA`N
h*G#<M
byte[] b = new byte[1024]; n3*UgNg%fK
int nRead; )X~#n
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) =Iy/cHK
{ Dw*Arc+3V
nStartPos += fileAccessI.write(b,0,nRead); -}<d(c
//if(nThreadID == 1) :;q>31:h
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &q"'_4
} KCl &H
hc6.#~i
@Mzz2&(dU
Utility.log("Thread " + nThreadID + " is over!"); ^J0zXe -d
bDownOver = true; l`G(O$ct
//nPos = fileAccessI.write (b,0,nRead); =p5?+3"@
} rQn{L{
catch(Exception e){e.printStackTrace ();} .B6`OX&k
} 'qdg:_L"
} yS+(<
^g-Fg>&M
C(xqvK~p
//打印回应的头信息 =zz+<!!
public void logResponseHead(HttpURLConnection con) A"0wvk)UcY
{ J &{qppN
for(int i=1;;i++) _IC,9bbg
{ G&.d)NfE
String header=con.getHeaderFieldKey(i); sE-x"c
if(header!=null) jk K#e$7
//responseHeaders.put(header,httpConnection.getHeaderField(header)); >6XDX=JVI
Utility.log(header+" : "+con.getHeaderField(header)); m**0rpA
else HgYc@P*b
break; B'<!k7Ewy
} NP$e-" 1
} dFx2>6AZt
fV*}c`
Go-wAJ>
public void splitterStop() Y+!Ouc!$
{ wH+FFXGJs
bStop = true; 4=~ 9v
} W)|c[Q\
t3pZjdLJd
B%TXw#|
} P8"6"}B;T
qbEKp HnB
7WgIhQ~
/* (W7;}gysh
**FileAccess.java t8t}7XD
*//文件访问(定位，写) gW'P`Oxw
package NetFox; &t~zD4u B
import java.io.*; $K+4C0wX`
Sjw2 j#Q
P/C&R-{')
public class FileAccessI implements Serializable{ 3w t:5 Im
UaH26fWs
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zhuyePn
RandomAccessFile oSavedFile; c"sj)-_
long nPos; P#w}3^
&7$,<9.
"kcpA#uD|
public FileAccessI() throws IOException 6e-#XCR{
{ \d `dV0X
this("",0); NS7@8 #C
} 7vii9Am7
h9w@oRp`~
44'=;/
public FileAccessI(String sName,long nPos) throws IOException n33JTqX
{ 1y},9ym
oSavedFile = new RandomAccessFile(sName,"rw"); fndK/~?]H
this.nPos = nPos; >{j,+$%kp
oSavedFile.seek(nPos); =$^Wkau
} _7rqXkp%
&=v/VRan[
<^CYxy
public synchronized int write(byte[] b,int nStart,int nLen) R#"U/8b>z
{ u^}7Vs .
int n = -1; V<7R_}^_7
try{ T[i7C3QS
oSavedFile.write(b,nStart,nLen); kb/|;!
n = nLen; v9Z lNA7m!
} v(qV\:s}m
catch(IOException e) `V]egdO
{ u&1j>`~qJ
e.printStackTrace (); =nJOaXR0
} g2+l@$W
XD;15a
:*mA,2s
return n; e*Uz#w:
} l84h%,
"WF( 6z#
>{O[t2&
} ?R|fS*e2EB
*\=2KIF'
aDm-X r
/* >/7KL2*
**SiteInfoBean.java DePV,.
*/ LL|_c4$Ky
package NetFox; 4q\.I+r^
qWRNHUd
%00k1*$
public class SiteInfoBean { Jo6~r-
]I{qp~^#n
844tXMtPB\
private String sSiteURL; //Site's URL vDu0
private String sFilePath; //Saved File's Path tb-OKZq
private String sFileName; //Saved File's Name Q3B'-BZe
private int nSplitter; //Count of Splited Downloading File j[$B\H
qPFG+~\c
lH#@^i|G
public SiteInfoBean() xFsB?d
{//nSplitter的缺省值为5 K^!e-Xi6
//default value of nSplitter is 5 ,omp F$%
this("","","",5); rK(x4]I l"
} "C$!mdr7
09}f\/
$\YLmG
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ;4-pupK~%
{ m[g< K
sSiteURL= sURL; |QAeQWP+1
sFilePath = sPath; &=s|
sFileName = sName; 6e$sA (a=i
this.nSplitter = nSpiltter; 9B!im\]O
4i+PiD:H
% +kT
} 37:b D
CX&yjT6`
(ybtXoQs
public String getSSiteURL() <F#*:Re_y
{ yNhscAMNn
return sSiteURL; Dyouk+08x
} +E q~X=x
/ K_e;(Y_
lRF_ k
public void setSSiteURL(String value) 48 c D3w
{ H y.3ccZ0
sSiteURL = value; y(c|5CQ
} t_dw}I
?l\gh1{C
%#Wg^l '
public String getSFilePath() 5CY@R
{ YA^wUx
return sFilePath; :Fi%Cef|
} 1^x2WlUm4
O?j98H Sya
=BqaGXr
public void setSFilePath(String value) ! kOl$!X4
{ S1H47<)UF
sFilePath = value; dVsAX(
} 4,w{rmj
0TuOY%+
6yu*a_
public String getSFileName() )F%wwc^r
{ g9([3pV,
return sFileName; sl^s9kx;C$
} %|D\j-~
6PzN>+t^y
qSpa4W[
public void setSFileName(String value) aiR|.opIb
{ MUCJ/GF*
sFileName = value; =XacG}_
} Cdt,//xrz
0'V-
pE(<XD3Q
public int getNSplitter() L6rs9su=7
{ {x&jh|f`g
return nSplitter; s!j(nUd/
} Eis%)oE
`jUS{ 3^
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public void setNSplitter(int nCount) R@7GCj
{ j;AzkReb
nSplitter = nCount; vHI"C %
} I(?|Ox9"?
} t'=~"?T/o
$@u^Jt, ?
MOqA$b
/* -X&!dV:= 4
**Utility.java xPfnyAo?%z
*/ 2=Y_Qrhi
package NetFox; 1(:=jOfk
rd"]@~v1
F;MT4*4
public class Utility { <_sT]?N#
RZV1:hNN
k9_VhR|!
public Utility() ;GSFQ:m[
{ #a'x)$2;R|
[#Nx>RY
Z z;<P
} {Jw<<<G
W &0@&U
//线程睡眠 ,I2reG
public static void sleep(int nSecond) YW$x:
{ e@2Vn? 5
try{ ]!tYrSM!
Thread.sleep(nSecond); 1&@wb'MBs.
} QnP?;
catch(Exception e) Pu%>j'A
{ wh7a|
e.printStackTrace (); >e$^#\D
} SG|i/K|7
} EkjK92cF
[>J~M!yu:r
//日志 S9"y@F <
public static void log(String sMsg) S~a:1 _Wl
{ P=sK+}5`q
System.err.println(sMsg); ZvnZ}t>?
} 1M~:]}*<
#`#aSqGmc
dW^_tzfF7
public static void log(int sMsg) oIL+@}u7
{ qiKtR
System.err.println(sMsg); 5.K$ X$+7}
} G}dOx}kT
} Lq $4.l[j
2W:?#h3
Zz)oMw
/* NX{-D}1X=
**TestMethod.java 7si*%><X
*/ agxSb^ 8tF
package NetFox; jQ\ MB
8.Own=G?
zRJKIm
public class TestMethod { p|9ECdU>;
dG~B3xg;5i
??%T
public TestMethod() pffw5Tc
{ ///xx/weblogic60b2_win.exe ZLio8
try{ d>"$^${
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); X @jYQ.
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ]I' xLh`
SiteFileFetch fileFetch = new SiteFileFetch(bean); -IsdU7}
fileFetch.start(); WWs[]zr
} v/00LR
catch(Exception e){e.printStackTrace ();} <:;:*s3]
}`/n2
KjfKo;T
} |XdrO
#z^1)7
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public static void main(String[] args) 6k=Wt7C
{ ;YXrG
new TestMethod(); er7/BE&
} 09;'z
} tG^?fc
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