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)); FGJ1dBLr
} xu%k~4cB,
for(int i=0;i<nEndPos.length-1;i++) =*.~BG
{ P;no?
nEndPos = nStartPos[i+1]; B@))8.h]
} gg/-k;@ Rf
nEndPos[nEndPos.length-1] = nFileLength; ]0OR_'?,
} J{<X7uB
} T<>,lQs(a
Q\vpqE!9
!F-w3 ]
//启动子线程 Kw^7>\
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; I][*j
for(int i=0;i<nStartPos.length;i++) H41?/U,{
{ *>}@7}f
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), S13nL^=i
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 6|=f$a
nStartPos,nEndPos,i); e%M;?0j
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); wQf-sk#
fileSplitterFetch.start(); {YC@T(
} 3=[mP,pLh
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8Fh)eha9f
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >Tx?%nQ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ,p a {qne
nEndPos = " + nFileLength); t?gic9 q
// fileSplitterFetch[nPos.length-1].start(); S hWJ72c
0mVNQxHI
gJ{)-\
//等待子线程结束 ~?}Emn;t
//int count = 0; kTB0b*V
//是否结束while循环 >U>(`r*
boolean breakWhile = false; -2[a2^a'
u=sp`%?
_[3D
while(!bStop) "sCRdx]_
{ eByz-,{P
write_nPos(); JQI: sj
Utility.sleep(500); `wVyb>T
breakWhile = true; 0d&6lqTo
^CX6&d
F>l] 9!P|m
for(int i=0;i<nStartPos.length;i++) !pW0qX\1n
{ _{KG 4+5\X
if(!fileSplitterFetch.bDownOver) dn3y\
{ 4$<JHo @.
breakWhile = false; =T@1@w
break; <'*LRd$1
} Q%G8U#Tm
} niyV8v
if(breakWhile) D>q9 3;p
break; X"Swi&4
NLqzi%s
T5h H
//count++; T8g$uFo
//if(count>4) %u'ukcL7
// siteStop(); ?tbrbkx
} 5j(k:a+!H
8Z~EwY*
vs4>T^8e
System.err.println("文件下载结束！"); ux4POO3C|
} L8B!u9%
catch(Exception e){e.printStackTrace ();} 7.oM J
} z} #JK?u
?@86P|19
ZECfR>`x
//获得文件长度 fJg+Ryo
public long getFileSize() PW0LG^xp`
{ `c$V$/IT
int nFileLength = -1; &D<yX~
try{ F^:3?JA_
URL url = new URL(siteInfoBean.getSSiteURL()); a7opCmL
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >(<f 0
httpConnection.setRequestProperty("User-Agent","NetFox"); H5|;{q:j
9 68Ez
9(Xn>G'iT
int responseCode=httpConnection.getResponseCode(); "tK=+f`NM
if(responseCode>=400) !N^@4*
{ ;uGv:$([g
processErrorCode(responseCode); YmG("z
return -2; //-2 represent access is error (ZlU^Gw#UB
} 307I$*%W
n$R)>nY
[-w%/D%@
String sHeader; ueNS='+m
53h0UL
ckn(`I
for(int i=1;;i++) uxz^/Gk
{ |7~<Is~*
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6S#Cl>v
//Utility.log(in.readLine()); <_+X 88
sHeader=httpConnection.getHeaderFieldKey(i); *4 n)
if(sHeader!=null) rJB}qYD
{ 8P`"M#fI
if(sHeader.equals("Content-Length")) :4|4=mkr
{ k5)om;.w
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); i XN1I
break; [Rb+q=z#
} k?}Zg*
} =(^3}x
else j<$2hiI/?&
break; eS!/(#T
} dRMx[7jVA
} []T8k9g/-
catch(IOException e){e.printStackTrace ();} AQ Ojit6p
catch(Exception e){e.printStackTrace ();} 4p wH>1
FI.\%x
I^]nqK
Utility.log(nFileLength); a'T;x`b8U,
Xa&kIq}(g
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return nFileLength; gGuO
} EM_d8o)`B
!u hT
$~kA B8z
//保存下载信息（文件指针位置） HZOMlOZ
private void write_nPos() *WZA9G#V5
{ JGZBL{8
try{ @6]JIJE
output = new DataOutputStream(new FileOutputStream(tmpFile)); `0svy}
output.writeInt(nStartPos.length); [>9is=>o.
for(int i=0;i<nStartPos.length;i++) jWgX_//!
{ +|f@^-
// output.writeLong(nPos); sos5Y}
output.writeLong(fileSplitterFetch.nStartPos); dWW.Y*339
output.writeLong(fileSplitterFetch.nEndPos); O&&~NXI\
} ;@J}}h'y
output.close(); 06jQE2z2R
} bd`P0f?
catch(IOException e){e.printStackTrace ();} H*6W q
catch(Exception e){e.printStackTrace ();} d=^z`nt !R
} /V By^L:
a.Vuu)+Quw
r<\u6jF
//读取保存的下载信息（文件指针位置） 0`H# '/
private void read_nPos() 0{mex4
{ (5~h"s
try{ {+Jv+J9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @|!z9Y*
int nCount = input.readInt(); Va8&Z
nStartPos = new long[nCount]; !9x}
nEndPos = new long[nCount]; h];I{crh
for(int i=0;i<nStartPos.length;i++) wY}@'pzX
{ LQ% `c
nStartPos = input.readLong(); Mihg:
nEndPos = input.readLong(); ,?3G;-
} %)n=x ne
input.close(); Pz^544\~ou
} _B0L.eF
catch(IOException e){e.printStackTrace ();} 45oR=Atn
catch(Exception e){e.printStackTrace ();} 0IpmRH/
} 0$njMnB2l
_4f;<FL
g .\[o@H
private void processErrorCode(int nErrorCode) W>LR\]Ti@
{ .^g p?
System.err.println("Error Code : " + nErrorCode); @XVTU
} r=4eP(w=
e# bn#
54/=G(F
//停止文件下载 `{Ul!
public void siteStop() qWw=8Bq
{ *h|U,T7ew
bStop = true; /j^
for(int i=0;i<nStartPos.length;i++) qb4z T
fileSplitterFetch.splitterStop(); o}!PQ#`M
Xeajxcop#
`2snz1>!j
} 8-i#8'/x
} _g.{MTQ
//负责部分文件的抓取 *2?@ |<(r
**FileSplitterFetch.java g5yJfRLxp
*/ ]{iQ21`a-
package NetFox; v:U-6W_)|
5m*,8]!-
nR~(0G,H
import java.io.*; hQi2U
import java.net.*; XRH!]!
OYd !v`<
1qch]1 ^G
public class FileSplitterFetch extends Thread { c:0L+OF}xY
xwr8`?]y
/\Ef%@
String sURL; //File URL q@qsp&0/
long nStartPos; //File Snippet Start Position dscgj5b1~
long nEndPos; //File Snippet End Position . ^u,.
int nThreadID; //Thread's ID TO_e^A#
boolean bDownOver = false; //Downing is over NgwbQ7)
boolean bStop = false; //Stop identical R@0R`Zs
FileAccessI fileAccessI = null; //File Access interface R2;
B6"0OIDY"
`gJ(0#ac
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException yr6V3],Tp
{ Kgv T"s.
this.sURL = sURL; 0erNc'e
this.nStartPos = nStart; :+Z%; Dc
this.nEndPos = nEnd; y2v^-q3
nThreadID = id; TV:9bn?r)
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :Al!1BJQ
} dI2 V>vk
=vPj%oLp'a
CAe!7HiR
public void run() GVz6-T~\>
{ @7u0v
while(nStartPos < nEndPos && !bStop) \GBuWY3B
{ K'xV;r7Nt
9$Y=orpWxr
0%B/,/PxD
try{ \^LFkp
URL url = new URL(sURL); $:6!H:ty
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wq{hF<
httpConnection.setRequestProperty("User-Agent","NetFox"); [KQi.u
String sProperty = "bytes="+nStartPos+"-"; 8(De^H lO
httpConnection.setRequestProperty("RANGE",sProperty); g7|@
Utility.log(sProperty); ]iWRo'
zqku e%^?-
[ )F<V!
InputStream input = httpConnection.getInputStream(); 7^Uv7<pw
//logResponseHead(httpConnection); yu|>t4#GT
N[hG8f
m'U0'}Ld};
byte[] b = new byte[1024]; WxDh;*am:
int nRead; "MsIjSu
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) hoP]9&<T
{ W)/#0*7
nStartPos += fileAccessI.write(b,0,nRead); =wJX0A|
//if(nThreadID == 1) ;a/E42eN;
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); TC('H[ ]
} y5r4&~04
V#HuIgf-
r%_djUd
Utility.log("Thread " + nThreadID + " is over!"); gUlo]!$
bDownOver = true; OI*H,Z"
//nPos = fileAccessI.write (b,0,nRead); 1 zZlC#V
} |)&%A%m
catch(Exception e){e.printStackTrace ();} W^Yxny
} F [M,]?
} J,hCvm
M:8R-c#![
s7<AfaJPF
//打印回应的头信息 HQ g^ h
public void logResponseHead(HttpURLConnection con) sK{e*[I>W
{ 45e~6",
for(int i=1;;i++) LLo;\WGZ
{ .>S!ji
String header=con.getHeaderFieldKey(i); IPk4 ;,
if(header!=null) $`c:&
//responseHeaders.put(header,httpConnection.getHeaderField(header)); sx%[=g+<2(
Utility.log(header+" : "+con.getHeaderField(header)); w(/S?d
else b-DvW4B
break; UZMd~|
} \zkg
} R5D1w+
!Ee:o"jG{
d~H`CrQE*
public void splitterStop() L#J1b!D&<6
{ +R&gqja
bStop = true; -~1~I e2
} *p U x8yB
Oz95
/7kC<
} AKC`TA*E
8=l%5r^cq
wp_0+$?s
/* u_enqC3
**FileAccess.java QV!up^Zso
*//文件访问(定位，写) CrLrw T
package NetFox; GJrG~T
import java.io.*; :> '+"M2r
pP_LR ks}
6Oq7#3]
public class FileAccessI implements Serializable{ #e"[^_C@!
mt .sucT
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 d0D]Q
RandomAccessFile oSavedFile; p{_" bB
long nPos; s<Ziegmw|g
eFgA 8kY)
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public FileAccessI() throws IOException 9w"*y#_
{ DQ3<$0
this("",0); h{Y",7]!
} LVGe]lD
l#o ~W`
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public FileAccessI(String sName,long nPos) throws IOException qGo.WZ$
{ 1zv'.uu.,
oSavedFile = new RandomAccessFile(sName,"rw"); $FVNCFN%
this.nPos = nPos; e6*8K@LHB
oSavedFile.seek(nPos); kVgTGC"L=
} fhiM U8(&
{)XTk&"
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public synchronized int write(byte[] b,int nStart,int nLen) ';CNGv -
{ )nkY_'BV
int n = -1; y(#e}z:
try{ D*jM1w_`
oSavedFile.write(b,nStart,nLen); -@'FW*b
n = nLen; @d'j zs
} VA%J\T|G2\
catch(IOException e) yWK)vju"
{ 4hB]vY\T
e.printStackTrace (); y29m/i:
} kiEa<-]
2y4bwi
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return n; 9up3[F$
} Rcuz(yS8
dtDFoETz
81F9uM0
} yi[x}ffdE
F9^S"qv$
LVyyO3e
/* F59 TZI
**SiteInfoBean.java }MySaL>
*/ ?ub35NLa
package NetFox; P55fL-vo|}
Uo49*Mr
h[ ZN+M
public class SiteInfoBean { Wwo0%<2y
+`4A$#$+y
6]N.%Y[(
private String sSiteURL; //Site's URL @Qe0! (_=
private String sFilePath; //Saved File's Path rv;3~'V
private String sFileName; //Saved File's Name BtZyn7a
private int nSplitter; //Count of Splited Downloading File g(g& TO
/v}`l
]~-r}`]
public SiteInfoBean() ZCw]m#lS
{//nSplitter的缺省值为5 f$( e\++
//default value of nSplitter is 5 hTkyz la
this("","","",5); kfNWI#'9
} M|-)GvR$J
`oJ [u:b
=N@t'fOr
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) G$PE}%X
{ =Qq+4F)MD
sSiteURL= sURL; =a!=2VN9y
sFilePath = sPath; iLT}oKF2N;
sFileName = sName; P>L +t`'
this.nSplitter = nSpiltter; 0(Ij%Wi,
a.'*G6~Qgw
:N@^?q{b
} dx]>(e@(t{
!k%#R4*>
^aQ"E9
public String getSSiteURL() NI5``BwpO
{ E]6 6]+;0_
return sSiteURL; l%ZhA=TKQ
} mmsPLv6
e)ZUO_Q$
BVm0{*-[|
public void setSSiteURL(String value) @;kSx":b
{ VpUAeWb
sSiteURL = value; Al'3?
} !BI;C(,RL
S'14hk<
WHI`/FM
public String getSFilePath() /=h` L,
{ ;=@0'xPEa-
return sFilePath; '|4!5)/K
} eQ"E
_U0f=m
VX/#1StC
public void setSFilePath(String value) i!cCMh8
{ J;%Xfx]
sFilePath = value; G`zm@QL
} <Qq*p
l@\FWWQ
FqifriLN
public String getSFileName() @6d[=!9
{ IAEAhqp
return sFileName; [2koe.?(
} fatf*}eln
|'.
8[>zG2
public void setSFileName(String value) W l16`9
{ yBRC*0+Vy
sFileName = value; {|\.i
} iOdpM{~*
B;WCTMy}
Q &t<Y^B
public int getNSplitter() Z= !*e~j@
{ zT[!o j7
return nSplitter; LF7SS;&~f
} f-2c0Bi
80;(Gt@<"
kN>!2UfNS
public void setNSplitter(int nCount) Sc
{ akT6^cP^
nSplitter = nCount; p:%loDk
} {iLT/i%
} i LAscb
l(q ,<[O
-^57oU
/* Z8oK2Dw
**Utility.java ASfaX:ke
*/ J$!iq|
package NetFox; @A5?3(e
EIQ p>|5
[9 RR8
public class Utility { N?>vd*
~,~eoW7
JG,%qFlk
public Utility() _l]fkk[T
{ hzRYec(
BSMwdr
)/EO&F
} ?rup/4|
Bw{I;rW{2
//线程睡眠 pD74+/DD
public static void sleep(int nSecond) T5:G$-qL(
{ [h:T*(R?
try{ eN~=*Mn(za
Thread.sleep(nSecond); 69 o7EA
} !3v1bGk
catch(Exception e) Wr5V`sM
{ TuYCR>P[
e.printStackTrace (); D)'bH5
} Z`BK/:vo3H
} Ib0ZjX6
BRYHX.}h\A
//日志 zA"`!}*
public static void log(String sMsg) _]*>*XfF(
{ &yol_%C
System.err.println(sMsg); TNr :pE<
} eNu7~3k}
OaZQ7BGq
=6#Eh=7N
public static void log(int sMsg) !&Pui{F
{ K!]/(V(}
System.err.println(sMsg); O<;3M'y\
} -FlzEZ
} o\)F}j&b#=
@{pLk4E
C=4Qlt[`
/* wIBO ^w\J
**TestMethod.java |qZ1|
*/ Bng@-#`/
package NetFox; )D82N`c2\i
#`X?=/q
{s{j~M
public class TestMethod { !1Cy$}w
QS]1daMIK<
U2~kJ
public TestMethod() d6sye^P
{ ///xx/weblogic60b2_win.exe e,XYVWY%
try{ _W'-+,
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :'&brp3ii=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 3J438M.ka
SiteFileFetch fileFetch = new SiteFileFetch(bean); hzbw>g+
fileFetch.start(); A:9?ZI/X
} f[^Aw(o
catch(Exception e){e.printStackTrace ();} 'W,jMju
c>~*/%+
m&?r%x
} ["e3Ez
o"BoZsMk
@Sbe^x
public static void main(String[] args) KX7>^Bt&k
{ tWa)_y
new TestMethod(); X~,aNRy
} WoRZW%
} @qlK6tE`
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