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)); `n+uA~
} !&%KJS6p4
for(int i=0;i<nEndPos.length-1;i++) pI@71~|R
{ l6zAMyau5
nEndPos = nStartPos[i+1]; 9WHE4'Sa
} l4gH]!/@
nEndPos[nEndPos.length-1] = nFileLength; q\tr&@4iC
} /OKp(u;)z
} +kI}O*s
lU 9o"2
c coi
//启动子线程 5a |[cR
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 4lo7yx
for(int i=0;i<nStartPos.length;i++) 51:5rN(_
{ #jbC@A9Pe
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l@4pZkdq
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ;apLMMsWC
nStartPos,nEndPos,i); 5?3v;B6
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); E2Sj IR}
fileSplitterFetch.start(); [w](x
} 2<7pe@c98
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W{Qb*{9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); {UH45#Ua
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", THl:>s
nEndPos = " + nFileLength); _9oKW;7f7
// fileSplitterFetch[nPos.length-1].start(); 4#t'1tzu#
&"u(0q
`&I6=,YLp
//等待子线程结束 _Q:ot'(~0-
//int count = 0; {9J|\Zz3
//是否结束while循环 W3l[a^1d
boolean breakWhile = false; s=$xnc}mf
$%U}k=-
$d1ow#ROgy
while(!bStop) xpZ@DK;
{ I N@ ~~
write_nPos(); UXZ3~/L5 O
Utility.sleep(500); qX&+
breakWhile = true; .0nT*LF
52^3N>X4X
hzbvR~rn
for(int i=0;i<nStartPos.length;i++) '3XOU.
{ :qS~"@?<
if(!fileSplitterFetch.bDownOver) Qc33CA
{ yO-2.2h
breakWhile = false; r E1ouz!D
break; '"Cqq{*
} W}F~vx.
} wz+mFf
if(breakWhile) t<`wK8)
break; E.yFCaL
6oKlr,.
2U%t
//count++; !:d\A
//if(count>4) #WA7}tHb
// siteStop(); W)`>'X`
} EQnU:a
[YQtX_;w
oCwep^P(v
System.err.println("文件下载结束！"); ;E}&{w/My
} x~l"'qsK
catch(Exception e){e.printStackTrace ();} 0"-H34M<D
} uUl;}W
dyqk[$(
?n<sN"
//获得文件长度 w8>lWgN
public long getFileSize() 7d{xXJ-
{ Yy!G?>hC
int nFileLength = -1; n n[idw
try{ 0o6r3xc;
URL url = new URL(siteInfoBean.getSSiteURL()); .K940& Ui
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); qoan<z7
httpConnection.setRequestProperty("User-Agent","NetFox"); wQ-BY"cK\
KW0KXO06a
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int responseCode=httpConnection.getResponseCode(); 7F~Jz*,B*W
if(responseCode>=400) vr>J$(F
{ GNG.N)q#C
processErrorCode(responseCode); : Q,O:
return -2; //-2 represent access is error q9zeN:><
} j%vxCs>
)W@
L7II>^"B
String sHeader; ),<h6$
"{{@N4^
PzjIM!>
for(int i=1;;i++) /|Gz<nSc
{ &=8ZGjR< }
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $ z+ =lF
//Utility.log(in.readLine()); yYC\a7Al4
sHeader=httpConnection.getHeaderFieldKey(i); DL_M#c`<
if(sHeader!=null) hHt.No
{ ;r;>4+zn\
if(sHeader.equals("Content-Length")) I tn?''~;
{ ]~WIGl"g
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +SRM?av
break; rI:]''PR
} F7p`zf@O]
} X bV?=
else -r_Pp}s
break; XF4NRs
} RvW>kATb_F
} I7ySm12}
catch(IOException e){e.printStackTrace ();} Erl@]P4
catch(Exception e){e.printStackTrace ();} or`"{wop
@[(%b{TE;
:Ea]baM"
Utility.log(nFileLength); {-IRX)m*
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k/xNqN(
return nFileLength; (w'k\y
} [s!cc:JR
KrECAc
@0:mP
//保存下载信息（文件指针位置） }>Lz\.Z/+[
private void write_nPos() ku5g`ho
{ "%t !+E>nr
try{ P[cGCmM
output = new DataOutputStream(new FileOutputStream(tmpFile)); YAF0I%PYU
output.writeInt(nStartPos.length); V> eJ
for(int i=0;i<nStartPos.length;i++) E<_+Tc
{ !I8(Y
// output.writeLong(nPos); $r)nvf`\
output.writeLong(fileSplitterFetch.nStartPos); Y0OVzp9 b
output.writeLong(fileSplitterFetch.nEndPos); !91<K{#A{
} In4T`c?kQ
output.close(); 20uR?/|@
} *r3u=oWb
catch(IOException e){e.printStackTrace ();} -aMwC5iR@
catch(Exception e){e.printStackTrace ();} K[|d7e
} jr5x!@rb
W/R-~C e
fm% Y*<Y"
//读取保存的下载信息（文件指针位置） Y)4D$9:
private void read_nPos() ~oBSf+N
{ KWV{wW=-
try{ [[u&=.Au
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ~Urj:l
int nCount = input.readInt(); yYTiAvN
nStartPos = new long[nCount]; ">RDa<H]
nEndPos = new long[nCount]; :!EOg4%i
for(int i=0;i<nStartPos.length;i++) >7V&pH'
{ M*c`@\
nStartPos = input.readLong(); sXSZ#@u,WN
nEndPos = input.readLong(); pKSVT
} Ec]cCLB
input.close(); <tTn$<b
} g'b)]Q
catch(IOException e){e.printStackTrace ();} eVWnD,'
catch(Exception e){e.printStackTrace ();} ]HP
} e{9(9qE"
T%F8=kb-9
[!:.9
private void processErrorCode(int nErrorCode) Hv>Hz*s_I
{ BO ^T :
System.err.println("Error Code : " + nErrorCode); "|"bo5M:
} @le23+q
R=M${u<t
yz2NB?)
//停止文件下载 g<{W\VOPm
public void siteStop() |3g:q
{ C31SXQ
bStop = true; 1<qq69x
for(int i=0;i<nStartPos.length;i++) ^Q_0Zq^H
fileSplitterFetch.splitterStop(); *%cI,}%
Pz+8u&~p
A|@d4+
} [H)p#x
} \9BIRY`
//负责部分文件的抓取 _hLM\L
**FileSplitterFetch.java @ B3@M
*/ |xaA3UA
package NetFox; o*QhoDjc
Da8qR+*x
,k@fXoW
import java.io.*; BiHBu8<
import java.net.*; sM~|}|p
+B'9!t4 2
A\.M/)Qo
public class FileSplitterFetch extends Thread { *Qg/W?"m
:/Nz' n
4Kt?; y ;
String sURL; //File URL 37!}8
long nStartPos; //File Snippet Start Position eA_1?j]E3
long nEndPos; //File Snippet End Position KFCzf_P!
int nThreadID; //Thread's ID Q_1EAxt
boolean bDownOver = false; //Downing is over M>_S%V4a
boolean bStop = false; //Stop identical s6).?oE
FileAccessI fileAccessI = null; //File Access interface T.W/S0#j3
^ tm,gh
F{f "xM
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 'J<KL#og
{ JCaT^KLz
this.sURL = sURL; Z)7 {e"5d
this.nStartPos = nStart; +V7*vlx-
this.nEndPos = nEnd; ZT_EpT=1
nThreadID = id; F+Lq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 *Xl&N- 04
} 0/(YH
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FQ(=Fnqn
public void run() ]b<k%
{ \&AmX8" [
while(nStartPos < nEndPos && !bStop) ^O[qCX
{ )Hlr 09t=]
w},k~5U^s
8u;l<^<
try{ ycCEXu2F
URL url = new URL(sURL); >48zRi\N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I#S6k%-'
httpConnection.setRequestProperty("User-Agent","NetFox"); 0Km{fZYq7;
String sProperty = "bytes="+nStartPos+"-"; {?BxVDD07
httpConnection.setRequestProperty("RANGE",sProperty); |'=R`@w~0
Utility.log(sProperty); 2lHJ&fck<
='OPU5(;O
a*S4rq@
InputStream input = httpConnection.getInputStream(); R[Kyq|UyVr
//logResponseHead(httpConnection); KH2a 2
^i#q{@g
cD2}EqZ 9
byte[] b = new byte[1024]; o $p*C
int nRead; ](-:l6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) tX Z5oG7
{ $N5}N\C:a
nStartPos += fileAccessI.write(b,0,nRead); V!3O 1
//if(nThreadID == 1) /o![%&-l
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 81H04L9K 7
} 1c+[S]7rY
-Vt*(L
eSywWSdf0
Utility.log("Thread " + nThreadID + " is over!"); =1yU& PJ
bDownOver = true; +&-/$\"
//nPos = fileAccessI.write (b,0,nRead); nvsuF)%9hZ
} Kv!CL9^LX7
catch(Exception e){e.printStackTrace ();} )UZ 's>O
} NBE)DL
} kUn55 l
SH5GW3\h
xC!,v 0&
//打印回应的头信息 07# ~cVI
public void logResponseHead(HttpURLConnection con) m[Px|A5{
{ t#}/VnSQ
for(int i=1;;i++) &FIPEe#n
{ KS1Z&~4
String header=con.getHeaderFieldKey(i); }O5c.3
if(header!=null) *#+XfOtF
//responseHeaders.put(header,httpConnection.getHeaderField(header)); q9yY%
Utility.log(header+" : "+con.getHeaderField(header)); 7oh6G
else =?0o5|u]
break; QpAK]
} eB<R@a|?S
} J/M1#sE
Mfuw y
\O^b|0zc
public void splitterStop() rH$0h2
{ mz3!HksZ"
bStop = true; = %\;7
} ,X)0+DNsq
j#9p0[
a(NN%'fDD
} /^ hB6_'D
$j)Er.!9|R
/4<eI3Z
/* _}EGk4E
**FileAccess.java G5Y 8]N
*//文件访问(定位，写) KaZ*HPe(
package NetFox; lnEc5J@c>i
import java.io.*; M4XnuFGB[w
gk"S`1>
Y<#WC#3=
public class FileAccessI implements Serializable{ ,pq<.?&E
LL7a20
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 '{@hBB+ D
RandomAccessFile oSavedFile; MP-A^QT
long nPos; 5^t68 WOl
z%Op_Ddp
P)XkqOGpT9
public FileAccessI() throws IOException 3o%JJIn&
{ fJtJ2xi
this("",0); P>z k
} [#fXmW>N/
f"~+mO
JR<#el
public FileAccessI(String sName,long nPos) throws IOException f\!*%xS;
{ CeNpJ
oSavedFile = new RandomAccessFile(sName,"rw"); NDm@\<MIzB
this.nPos = nPos; IpXg2QbN
oSavedFile.seek(nPos); if9I7@
} @]1E~
VjS %!P
JUok@6
public synchronized int write(byte[] b,int nStart,int nLen) ^)m]j`}IGb
{ @#c(4}^ <w
int n = -1; f#pT6
try{ sZ{Kl\1@
oSavedFile.write(b,nStart,nLen); )NGBA."t
n = nLen; VHsuC$3W
} c2Ua!p(c
catch(IOException e) I1=YSi;A
{ >G92k76G
e.printStackTrace (); m0t5oO
} WW2VW-Hk
4f~CG r
46o3F"
return n; [-f0s;F1%
} MeW8aLr
DZ?>9W{
N+rLbK*
} ^2[0cne
U5jY/e_
6*Qn9Q%p-
/* 1b+B
**SiteInfoBean.java HNxJ`x~Z~
*/ "ZEJL.Wy
package NetFox; 0I* ^VGZ
Z`v6DfK}
O66\s q
public class SiteInfoBean { &ME[H
%4Ylq|d
@Ytsb!!
private String sSiteURL; //Site's URL k ~lj:7g~
private String sFilePath; //Saved File's Path oJVpNE[3]
private String sFileName; //Saved File's Name d}3<nz,
private int nSplitter; //Count of Splited Downloading File I&3L1rl3{*
F IDNhu
l]Jk }.
public SiteInfoBean() m1a0uEA G
{//nSplitter的缺省值为5 >Y?B(I2e
//default value of nSplitter is 5 R!lNm,i
this("","","",5); aD8cqVhM3&
} |jJC~/WR
)I9AF,K
Y=sRVypJ
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Mii-Q`.:
{ Na=9ju
sSiteURL= sURL; VG*BAFs
sFilePath = sPath; -v8Jn#f
sFileName = sName; Qf0$Z.-
this.nSplitter = nSpiltter; w~afQA>
k{Vc5F
`0uKJFg
} z{bMW^F
]|<PV5SY3.
V:9|9$G
public String getSSiteURL() J4 .C"v0a
{ [Tby+pC
return sSiteURL; h`Vb#5ik
} 73P=<3
IhwJYPLF
9~I\WjB "
public void setSSiteURL(String value) {J%Na&D
{ P5*:r3>
sSiteURL = value; ZZA!Y9ia2
} 4%LG9hS
L7_(KCh
ZD/>L/
public String getSFilePath() 9xP{#Qa
{ K20n355uE
return sFilePath; TDBWYppM
} x=Qy{eIe
\)eHf 7H
KGxF3xS*7
public void setSFilePath(String value) Gg|'T}0X
{ 4*&x% ~*
sFilePath = value; yZ~<! 5.P
} EXH{3E54)`
SJoQaR,)>
yc|C}oQF
public String getSFileName() "5 PP<A,F(
{ n{d}]V@
return sFileName; QG?7L_I
} sqi~j(&\1
vD D !.i
m8n!<_NFt(
public void setSFileName(String value) Y;6<AIx>
{ #QXv[%k
sFileName = value; Wg[?i C*~
} g9}u6q
Y'i0=w6G
V2g,JFp&
public int getNSplitter() .3?'+KZ,
{ +L;[-]E8
return nSplitter; D%(9ot{!e
} ^c83_93)R
"h_]it};C
Wv_5sPqLW
public void setNSplitter(int nCount) fKOm\R47
{ V]L$`7G
nSplitter = nCount; }oYR.UH
} VH4P|w[YF
} &JAQ:([:
fU@}]&
7U:,:=
/* *h1Zqb
**Utility.java kMKI=>s+
*/ B/q/sC
package NetFox; r/HKxXT
0t}=F4@&a
<Xm5re.
public class Utility { Oh6;o1UI
"8ILV`[
B3O^(M5W
public Utility() 5IW^^<kiu
{ |}^[f]
@pQv}%
-?e~dLu
} |(}uagfrd
G\Hck=P[$3
//线程睡眠 q?[{fcNh$
public static void sleep(int nSecond) z~4L=tA(
{ {-^>) iJqt
try{ .2Q`. o)
Thread.sleep(nSecond); nuw90=qj!]
} (Ew o
catch(Exception e) {5.,gb@6
{ LoOyqJ,
e.printStackTrace (); l6xC'c,jg
} =ADAMP
} I m_yY
c1wgb8
//日志 dS0G+3J&+E
public static void log(String sMsg) \>cZ=
{ 9XT6Gf56
System.err.println(sMsg); `>?\MWyu
} .}ohnnJB0
fTY@{t
KK(x)(
public static void log(int sMsg) on*?O O'
{ V?Lf&X?
System.err.println(sMsg); o80pmy7@
} x?:WR*5w
} g0rdF
eQcy'GA06
A&$!s)8z
/* H b]
**TestMethod.java o4Fh`?d}
*/ 1dfA 8=L,s
package NetFox; '0H+2
5ez"B]&T
5zpk6FR$
public class TestMethod { mt fDl;/D
H\8i9RI
+SPC@E_v
public TestMethod() -5p=gO
{ ///xx/weblogic60b2_win.exe G8QJM0VpS
try{ xVfJ]Y
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); QlJCdCSy
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t1Hd-]28V
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;TmwIZ
fileFetch.start(); D: JGd$`
} *X%`MN
catch(Exception e){e.printStackTrace ();} BTjF^&`
x9Gm)~
Ip8 Ap$
} lxbbyy25
PwF}yxkI
Ng'f u|
public static void main(String[] args) -jC. dz
{ WRVKh
new TestMethod(); Fj1/B0acS
} '(2G qX!
} |+!Jr_ By
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