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)); #%8)'=1+4?
} L]Xx-S
for(int i=0;i<nEndPos.length-1;i++) pAqPHD=
{ O*lIZ,!n
nEndPos = nStartPos[i+1]; 7xY&7 x(v
} nr8#;D
nEndPos[nEndPos.length-1] = nFileLength; ,aq>9\pi
} +fKV/tSWi
} ;8 *"c
%rf6>
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//启动子线程 XMykUr e|
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {X<_Y<
for(int i=0;i<nStartPos.length;i++) MtgY `p
{ 44t;#6p@%>
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \VI0/G)L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), lp5'-Jo
nStartPos,nEndPos,i); k^cnNx
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); '/rU<.1
fileSplitterFetch.start(); =3rf}bl2
} :oYSvK7>
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *-.`Q
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]/3!t=La
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", s jaaZx1
nEndPos = " + nFileLength); p2fzbBt
// fileSplitterFetch[nPos.length-1].start(); t$p%UyVE
LaZ @4/z!
8Fbt >-N<\
//等待子线程结束 Im};wJ&
//int count = 0; (lq%4h
//是否结束while循环 bE=[P}E
boolean breakWhile = false; DY/%|w*L
hOV5WO\
7:=(yBG
while(!bStop) EM1HwapD
{ V?>&9D"m
write_nPos(); k8SY=HP
Utility.sleep(500); F x$W3FIO]
breakWhile = true; %s5(''a.
33a}M;vx
a@9W'/?igk
for(int i=0;i<nStartPos.length;i++) ep`8LQf
{ M\Wg|gpy
if(!fileSplitterFetch.bDownOver) rTOex]@N
{ (9'q/qgTO
breakWhile = false; ZEpu5`
break; 9"/=D9o9
} ;NAKU
} ;<6S\
if(breakWhile) Q84XmXm|
break; t-iQaobF
}dqOE-"I"n
.vIRz-S
//count++; }N,v&B
//if(count>4) C.H(aX)7
// siteStop(); *+2BZZwT
} W'E3_dj+
VG$%Vs
Tc/<b2\g
System.err.println("文件下载结束！"); ycEp,V;[Z
} hh.`Yu L
catch(Exception e){e.printStackTrace ();} LW/> %
} ]n'.}"8Kn
nDLiER;U
%x}Unk
//获得文件长度 }XRfHQk
public long getFileSize() YluvWHWi
{ OU^I/TU
int nFileLength = -1; &sXk!!85:
try{ #"H<k(-Cz
URL url = new URL(siteInfoBean.getSSiteURL()); %RzkP}1>E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Lm0q/d2|\X
httpConnection.setRequestProperty("User-Agent","NetFox"); us<dw@P7{
Y9%zo~]-W'
|="Y3}a
int responseCode=httpConnection.getResponseCode(); (9] =;)
if(responseCode>=400) 5twG2p8
{ b`cH.v
processErrorCode(responseCode); f,3K;S-he:
return -2; //-2 represent access is error 83'rQDo)G
} a", 8N"'
Q(Pc
k>E/)9%ep2
String sHeader; 8)b*q\O'
n2["Ln mO
Np.<&`p!
for(int i=1;;i++) =^zOM6E1ZF
{ ZKB27D_vg>
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); h<WTN_i}
//Utility.log(in.readLine()); +<f+kh2L
sHeader=httpConnection.getHeaderFieldKey(i); Qi9M4Yv
if(sHeader!=null) jq|fIP
{ 6}\J-A/
if(sHeader.equals("Content-Length")) 'X_%m~}N
{ \@^` G
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^~bAixH^k
break; \#"&S@%c
} q _:7uQ
} /q"8sj/
else )G#O#Yy
break; 3Ea/)EB]
} y99|V39'
} Xcg+ SOB
catch(IOException e){e.printStackTrace ();} xp\6,Jyh
catch(Exception e){e.printStackTrace ();} h<!!r
sX`by\s,
|~Vq"6`
Utility.log(nFileLength); G49`a*Jn
!4$o*{9Lx:
e\*N Lj_(
return nFileLength; S3c%</'
} /AUX7 m.8
~(^?M
VlxHZ
//保存下载信息（文件指针位置） edlsS}8^
private void write_nPos() \YsLVOv%:d
{ v.Q+4 k
try{ U/\LOIs
output = new DataOutputStream(new FileOutputStream(tmpFile)); N'%l/
output.writeInt(nStartPos.length); r+h$]OJ
for(int i=0;i<nStartPos.length;i++) irGgo-x
{ 1%N[DA^<\
// output.writeLong(nPos); jF{\=&fU
output.writeLong(fileSplitterFetch.nStartPos); QGXR<Y
output.writeLong(fileSplitterFetch.nEndPos); njb{
} "?"+1S
output.close(); O[9A}g2~
} ,sp((SF]1
catch(IOException e){e.printStackTrace ();} qa?0GTAS
catch(Exception e){e.printStackTrace ();} V%FWZn^
} ]sB%j@G
d{]2Q9g
?T'a{~]R
//读取保存的下载信息（文件指针位置） ;7mE%1X
private void read_nPos() >WY\P4)k
{ (<Kf
try{ q]P$NeEiZ"
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); uCf _O~
int nCount = input.readInt(); *p^*>~i9)
nStartPos = new long[nCount]; ygqWy1C
nEndPos = new long[nCount]; Mqmy*m[U
for(int i=0;i<nStartPos.length;i++) V_=7q=9mV
{ p8E6_%Rw
nStartPos = input.readLong(); '77Gg
nEndPos = input.readLong(); TK Ec^
} l3YS_WBSn
input.close(); [4\n(/
} GbBz;ZV%z,
catch(IOException e){e.printStackTrace ();} c7 O$< F
catch(Exception e){e.printStackTrace ();} 5 r&n
} a,?u 2
JZoH -
$HFimU,V=0
private void processErrorCode(int nErrorCode) 0JV|wd8j
{ ,4S6F HK
System.err.println("Error Code : " + nErrorCode); OZ Hfd7K4A
} +^|=MK%
;PWx#v+vwF
1&utf0TX6q
//停止文件下载 .J2tm2]"EZ
public void siteStop() lXu6=r
{ :v8~'cZ
bStop = true; $`|\aXd[C*
for(int i=0;i<nStartPos.length;i++) >8w=Vlp
fileSplitterFetch.splitterStop(); e]3b0`E
c+G%o8
sN@=Ri?\
} ko`KAU<T_
} SfGl*2
//负责部分文件的抓取 ?w>-ya
**FileSplitterFetch.java /jd.<r=_I
*/ 4cJka~
package NetFox; 'a=QCO 0
(L!#2Jy
*#sY-Gd
import java.io.*; )'axJ
import java.net.*; ~x g#6%<=
f9?f!k
=(p]L
public class FileSplitterFetch extends Thread { dC8,
,<]~/5-f
>~rytg]f
String sURL; //File URL A=\:b^\
long nStartPos; //File Snippet Start Position CdTE~O<)
long nEndPos; //File Snippet End Position &u9@FFBT8
int nThreadID; //Thread's ID n~?n+\.&a
boolean bDownOver = false; //Downing is over Aiqn6BX{
boolean bStop = false; //Stop identical G!5~`v
FileAccessI fileAccessI = null; //File Access interface Tu}?Q.pKo
&K-0ld(;
G[a&r
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException \@GKVssw
{ W=!di3IA
this.sURL = sURL; FYX"q-Z
this.nStartPos = nStart; c"`CvQO64
this.nEndPos = nEnd; _|s'0F/t
nThreadID = id; {M P(*N
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )~ghb"K
} a>BPK"K2
t}f,j^`e
~cb7]^#u1l
public void run() "\l#q$1h
{ asKAHVT(
while(nStartPos < nEndPos && !bStop) nlR7V.
{ NrWgaPO)i
=4:]V\o):'
)o_Pnq9_
try{ 1'BC R
URL url = new URL(sURL); `z?h=&N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ) 0|X];sD
httpConnection.setRequestProperty("User-Agent","NetFox"); .dTXC'
String sProperty = "bytes="+nStartPos+"-"; H{VJS Jc{
httpConnection.setRequestProperty("RANGE",sProperty); )]3_o!o
Utility.log(sProperty); ,p9>/)l
R}HNi(%"
dNT<![X\
InputStream input = httpConnection.getInputStream(); W&;,7T8@
//logResponseHead(httpConnection); H.*aVb$
+VRM:&
9]PMti
byte[] b = new byte[1024]; T<K/bzB3z
int nRead; t-VU&.Y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) XSe\@t~&g
{ D;+sStZK3
nStartPos += fileAccessI.write(b,0,nRead); +$ 0wBU
//if(nThreadID == 1) 4LkW`Sbm
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); zL/rV<
} (Kb_/
ECr}7R%
xpB*>zb
Utility.log("Thread " + nThreadID + " is over!"); Wr;9Mz&{
bDownOver = true; -5d^n\CDK
//nPos = fileAccessI.write (b,0,nRead); J @^Ypq
} #B!<gA$/
catch(Exception e){e.printStackTrace ();} 91ndr@*|
} c^x5 E`{
} @"O|[%7e
gfly?)VnF
c,FZ{O@
//打印回应的头信息 0artR~*}
public void logResponseHead(HttpURLConnection con) g&?{^4t]
{ l$g \t]
for(int i=1;;i++) =a!_H=+4
{ \<W/Z.}/
String header=con.getHeaderFieldKey(i); F6gU9=F1<
if(header!=null) 'QC'*Hl
//responseHeaders.put(header,httpConnection.getHeaderField(header)); /xw}]Fa5
Utility.log(header+" : "+con.getHeaderField(header)); G:i>MJbxT
else nr- 32u
break; AY_GD ^
} D&!c7_^
} hK 1 H'~c
K2!GpGZu
qw6i|JM%
public void splitterStop() _DLELcH Y
{ 0rCQz3gh1
bStop = true; uG=~kO
} ~+CEek
fRomP-S
bO+]1nZ.
} <KBS ;t="1
a9g~(#?a
(qDPGd*1
/* k]9+/$
**FileAccess.java tx,q=.(
*//文件访问(定位，写) @!p0<&R@x
package NetFox; @|EWif|
import java.io.*; sr-tZ^d5S?
e&-MP;kgW9
aI_[h v
public class FileAccessI implements Serializable{ <7_s'UAL!
?ZP@H _w6}
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 tui5?\
RandomAccessFile oSavedFile; Hd57Iw
long nPos; L'u*WHj|v
'9@AhiNV
#T++5G
public FileAccessI() throws IOException K8RV=3MBLD
{ l-$5CO
this("",0); U<I]_]
} t 09-y
aW_Pv~
N^4CA@'{
public FileAccessI(String sName,long nPos) throws IOException xiOAj"}~
{ c'SjH".[
oSavedFile = new RandomAccessFile(sName,"rw"); ;$'D13
this.nPos = nPos; `wKd##v'@
oSavedFile.seek(nPos); Af Y]i
} U3~rtc*
y 'Ah*h
A$70!5*
public synchronized int write(byte[] b,int nStart,int nLen) bMB*9<c~
{ <RuLIu
int n = -1; $g_|U:,
try{ .S*VYt%K7
oSavedFile.write(b,nStart,nLen); <FfmDR
n = nLen; 0( q:K6zI}
} )3.=)?XW
catch(IOException e) TgA>(HcO
{ _o? I=UN2:
e.printStackTrace (); `t3w|%La}
} LjCUkbzQF
rqz48~\lJ
zE+^WeH|
return n; =rA]kGx
} [@Mo3]#\
m>djoe
rlY n"3%
} jEn9T
$bl<mG%#9
?-JW2 E"uT
/* '0v]?mM
**SiteInfoBean.java iLQ;`/j
*/ l~mj>$
package NetFox; Zi{vEI]
U#:N/ts*(
X 4\V4_
public class SiteInfoBean { <l5s[
Cd|rDa
80K"u[
private String sSiteURL; //Site's URL eW;c 3<
private String sFilePath; //Saved File's Path r4Xaa<
private String sFileName; //Saved File's Name S 9|^VU
private int nSplitter; //Count of Splited Downloading File 8>`8p0I$+
Oj '^Ww m
$B`ETI9g-N
public SiteInfoBean() Vg}+w Nt5
{//nSplitter的缺省值为5 cN`P5xP'
//default value of nSplitter is 5 VFq7nV/O
this("","","",5); IV~5Y{(l
} m -0}Pe9L
a:KL{e[
G"ixw
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hqa6aYY x
{ 3gYtu-1
sSiteURL= sURL; 1n[wk'}qf4
sFilePath = sPath; 8X/SNRk6p
sFileName = sName; vAjog])9s
this.nSplitter = nSpiltter; !-t"}^)
f|Nkk*9$
>M^:x-mib
} >sQf{uL
q#K0EAgC
mR$0Ij/v
public String getSSiteURL() :s1.TQ;Y(
{ eQ,VK`7X
return sSiteURL; Y.kc,~vYL
} /#j)GlNp:
`5n^DP*X
SeuDJxqopD
public void setSSiteURL(String value) !&5|:96o
{ 89t"2|9 u
sSiteURL = value; /Mj|Px%
} 2fXwJG'
8! /ue.T
(yoF
public String getSFilePath() ZCA= n
{ @2`nBtk
return sFilePath; ng9_c
} Wu/:ES)C
`|mV~F|
c*i,z
public void setSFilePath(String value) \eAV: qV
{ J!">L+Zcx
sFilePath = value; &'Xgf!x
} 9*XT|B
ilZQ/hOBH
{asq[;]
public String getSFileName() `l %,4qR
{ {REGoe=W%
return sFileName; >h.HW
} rr>6;
GC_c.|'6[
)~`UDaj_
public void setSFileName(String value) _Ud!tK*H
{ +pQ3bX
sFileName = value; A)&CI6(
} w|NId,#f
M!X^2
(EH}lh}%
public int getNSplitter() i~)EUF
{ ,W;|K 5
return nSplitter; "U$](k.<VA
} }}bMq.Q'
[.6bxK
8"p rWAN
public void setNSplitter(int nCount) vP\6=71Y
{ Ggy?5N7P
nSplitter = nCount; #w8.aNU+]
} h iK}&
} F{_,IQ]U
0g; o6Fg
I!Mkss xc
/* ^ > ?C
**Utility.java ^/#8 "
*/ h"'}Z^
package NetFox; Fc=6*.hy
L\!Oj5
4,?beA
public class Utility { /c6]DQ<?
`wr*@/P
J|@D @\?7
public Utility() 3o"l sly
{ +}Mm5^6*
?.n1t@sG&
7xR:\FBa^
} ` k(Q:
nc1?c1s,f
//线程睡眠 vZs~=nfi#|
public static void sleep(int nSecond) jVHS1Vsei
{ _>r(T4}]
try{ jhBfy|Ftu
Thread.sleep(nSecond); P*OT&q
} (cV1Pmn
catch(Exception e) ]z| 2
{ C5jt(!pi
e.printStackTrace (); a^ys7UV
} .F[5{XV
} t:v>W8N53
P0U&+^W"9
//日志 4ElS_u^cP7
public static void log(String sMsg) C~'.3Q6
{ [fELf(;(
System.err.println(sMsg); V|*3*W
} [57`V&c5
8@|{n`n]
\< a^5'
public static void log(int sMsg) xsNOjHk
{ mS49l
System.err.println(sMsg); zAev@+.ld
} 91DevizXx
} z46Sh&+
=h+-1zp{M^
=kzHZc
/* U-U(_W5&
**TestMethod.java kf#S"[/E
*/ NzN"_ojM
package NetFox; Zv?"1Y< L
NL2D,
Q]/{6:C
public class TestMethod { %:Y(x$Qy
%*Vr}@BA)
5KIhk`S
public TestMethod() lhf5[Rp
{ ///xx/weblogic60b2_win.exe l)'*jZ
try{ sE!g!ht
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); u yE#EnsH
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ,f<J4U:Y
SiteFileFetch fileFetch = new SiteFileFetch(bean); jM-5aj[K
fileFetch.start(); H ]!P[?
} Vs Z7n~e
catch(Exception e){e.printStackTrace ();} qv4r!x
6\.LG4@LO
_::ssnG3jT
} ikb77?.
\((5Sd
@=Dc(5`[
public static void main(String[] args) ?ef7%0
{ yf-2E_yB
new TestMethod(); (T&(PCw|
} Ug4o2n0sk
} 1Tev&J
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