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)); rZ_>`}O2
} VohhQ
for(int i=0;i<nEndPos.length-1;i++) 5)zn:$cz
{ 4c~>ci,N?(
nEndPos = nStartPos[i+1]; kqvow3u
} W[NEe,.>
nEndPos[nEndPos.length-1] = nFileLength; J NC
} n,P5o_^:
} Swtbl`,
:9l51oE7
\g-j9|0
//启动子线程 p4VqV6LwD
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; LF*Q!
for(int i=0;i<nStartPos.length;i++) |0bc$ZY:
{ 2aw&F Z?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,/&Zw01dGN
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), }tST)=M`
nStartPos,nEndPos,i); ^T4Ay=~{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ;52'}%5
fileSplitterFetch.start(); Jf:,y~mV
} +rNkN:/L
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), H L<s@kEZ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); tn/T6C^)
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <XQ.A3SG!
nEndPos = " + nFileLength); HTz+K6&
// fileSplitterFetch[nPos.length-1].start(); mnF}S5[9
P\~{3U
vxN0,l
//等待子线程结束 Cd#E"dY6
//int count = 0; ]_*S~'x
//是否结束while循环 =lr)gj
boolean breakWhile = false; ARh6V&Hi-
w#G2-?aj
KA]*ox6j;
while(!bStop) yno('1B@
{ E@QA".
write_nPos(); 6k])KlJ2;
Utility.sleep(500); 4ax|Vb)D
breakWhile = true; W^g[L:s
w,.qCpT$_
=~FG&rk^
for(int i=0;i<nStartPos.length;i++) (N~$x
{ ^E>CGGS4
if(!fileSplitterFetch.bDownOver) x.DzViP/
{ ro| vh\y
breakWhile = false; {^q)^<#JT
break; z>vtEV))
} +6W(z3($
} }4c/YP"a'E
if(breakWhile) 2BB<mv K4
break; Ef7:y|?
|qjZ38;6
#I\Y=XCY
//count++; Mpx/S<Z
//if(count>4) z YDK $
// siteStop(); eS!C3xC;J]
} "/%89 HMD
(L69{n
&d$~6'x*
System.err.println("文件下载结束！"); PjqeE,5
} XYbyOM VI
catch(Exception e){e.printStackTrace ();} ?{J!#`tfV
} A[/I#Im7
):6-
{E,SHh
//获得文件长度 )3E,D~1e%
public long getFileSize() cwtD@KC[B
{ g@nk.aRw
int nFileLength = -1; SX+RBVZU
try{ #n})X,ip2
URL url = new URL(siteInfoBean.getSSiteURL()); Sgj/s~j~1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); )r!e2zc=Q
httpConnection.setRequestProperty("User-Agent","NetFox"); V7<eQ0;m
Px4/O~bLk
/8CY0Ey
int responseCode=httpConnection.getResponseCode(); *{/@uO
if(responseCode>=400) F&@|M(
{ ]A:(L9
processErrorCode(responseCode); sB7" 0M
return -2; //-2 represent access is error OeTu?d&N
} ()|3
!L\'Mk/=A
r+gjc?Ol
String sHeader; $B _Nc*_e
SPwPCI1?
6$e]i|e
for(int i=1;;i++) (r F?If
{ 8$~3ra
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jUY+3"?
//Utility.log(in.readLine()); ( tn< VK.
sHeader=httpConnection.getHeaderFieldKey(i); !$kR ;Q"/
if(sHeader!=null) wJIB$3OT
{ Ph)|j&]
if(sHeader.equals("Content-Length")) 6v47 QW|'
{ O-GxUHwWr
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %Y',|+Arx
break; z}APR@?`n8
} P/aDd@j
} t.=Oj
else 5+L8\V9;
break; :('I)C
} X4I]9t\
} xXOw:A'
catch(IOException e){e.printStackTrace ();} XS/n>C
catch(Exception e){e.printStackTrace ();} V*qY"[
{8m1dEC^@Q
_Y#Bm/*
Utility.log(nFileLength); {%7<"
~I$}#
/2w@K_Px6
return nFileLength; qX@9N=g`#O
} w6U @tW
#O|lfl>}
8ui=2k(
//保存下载信息（文件指针位置） TG]}X\c+V|
private void write_nPos() dQ6GhS~
{ Mo|yv[(K,
try{ jsWX 6(=
output = new DataOutputStream(new FileOutputStream(tmpFile)); YN^jm
output.writeInt(nStartPos.length); on50+)uN
for(int i=0;i<nStartPos.length;i++) J#@lV
{ zPBfiK_hV
// output.writeLong(nPos); .eTk=i[N-
output.writeLong(fileSplitterFetch.nStartPos); okDJ(AIV+
output.writeLong(fileSplitterFetch.nEndPos); wP`sXPSmIu
} !aeNq82
output.close(); PW^ 8;[\QP
} ;IhPvff
catch(IOException e){e.printStackTrace ();} 9HKf^+';n
catch(Exception e){e.printStackTrace ();} 3kw}CaZ6
} sRi%1r7
\^s2W:c
1*c>I@I;
//读取保存的下载信息（文件指针位置） |Mlh;
private void read_nPos() )k~1,
{ <ge}9pU)o^
try{ wT%"5:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); A;t zRe
int nCount = input.readInt(); uQ1jwYK`7
nStartPos = new long[nCount]; -$L(y@%X^
nEndPos = new long[nCount]; X7&U3v
for(int i=0;i<nStartPos.length;i++) L]>4Nd
{ xN"wF-s4?
nStartPos = input.readLong(); w`Xg%*]}
nEndPos = input.readLong(); ^BNp`x;;`
} #NMJZ
input.close(); x\]z j!
} SJ[AiHR
catch(IOException e){e.printStackTrace ();} 6`W|V+6|7
catch(Exception e){e.printStackTrace ();} TU-c9"7M~
} MA"#rOcP
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2:~cJk{
private void processErrorCode(int nErrorCode) /=ACdJ
{ \bRy(Z)
System.err.println("Error Code : " + nErrorCode); 2YluJ:LN
} ex0oAt^
`{L{wJ:&a
Z fqQ{_
//停止文件下载 ' 3VqkQ4
public void siteStop() PC0HH
{ O(Td:Zdp
bStop = true; OaNc9c"
for(int i=0;i<nStartPos.length;i++) <vLdBfw&N
fileSplitterFetch.splitterStop(); i :EO(`
c _p[yS
kU(kU2u%9
} #!1IP~
} Yg|"-
//负责部分文件的抓取 BDp:9yau
**FileSplitterFetch.java rFO_fIJno
*/ 9nO(xJ"e4
package NetFox; 'tut4SwC
pMDH
{70Ou}*
import java.io.*; ~K%k 0kT
import java.net.*; Md?acWE*L
c+wuC,
WN1Jm:5YV
public class FileSplitterFetch extends Thread { ]'6'<S
K7S754m
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String sURL; //File URL cp|:8 [
long nStartPos; //File Snippet Start Position n{z8Ao%
long nEndPos; //File Snippet End Position iA&oLu[y3
int nThreadID; //Thread's ID qz87iJp&
boolean bDownOver = false; //Downing is over !6{Jq]
boolean bStop = false; //Stop identical j7,13,t1-
FileAccessI fileAccessI = null; //File Access interface '#KA+?@
7\f{'KL
gINwvzW{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "B~WcC
{ _Ws#UL+Nq
this.sURL = sURL; 4*H(sq
this.nStartPos = nStart; tr5'dX4]
this.nEndPos = nEnd; K:uQ#W.&
nThreadID = id; f%L:<4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 c,.0d
} l$=Gvb
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=>e?l8`%
public void run() 'Z59<Ya&x
{ f>O54T .L.
while(nStartPos < nEndPos && !bStop) <3)|44.o&
{ k+f1sV[4}
t[/\KG8
y~x#pC*w
try{ |1lf(\T_
URL url = new URL(sURL); $vW^n4!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F:M/z#:~
httpConnection.setRequestProperty("User-Agent","NetFox"); fJvr+4i4k
String sProperty = "bytes="+nStartPos+"-"; -*r[
httpConnection.setRequestProperty("RANGE",sProperty); HE@-uh
Utility.log(sProperty); $]nVr(OZ_
avmcGyL
]&' jP
InputStream input = httpConnection.getInputStream(); O(WEgz
//logResponseHead(httpConnection); mn(/E/
FLK"|*A
?ISI[hoc
byte[] b = new byte[1024]; "k/;`eAP
int nRead; =!(S<];
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) W;q#ZD(;
{ %N7gT*B:
nStartPos += fileAccessI.write(b,0,nRead); eSJAPU(D
//if(nThreadID == 1) -<]\l3E&J
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Av@&hD\
} ;tXB46
>c}:
q|R+x7x
Utility.log("Thread " + nThreadID + " is over!"); ^8b~ZX
bDownOver = true; ! Zno[R
//nPos = fileAccessI.write (b,0,nRead); QjehDwt|
} F19;RaP+
catch(Exception e){e.printStackTrace ();} %uh R'8"
} l}dj{s
} A>4l/
+GRxHuW,
K3a>^g
//打印回应的头信息 L-`(!j
public void logResponseHead(HttpURLConnection con) Q-M rH
{ 7ytm.lU
for(int i=1;;i++) .L~fFns/
{ [t {vYo
String header=con.getHeaderFieldKey(i); _e;N'DZ
if(header!=null) O\LjtMF
//responseHeaders.put(header,httpConnection.getHeaderField(header)); mipi]*ZfXE
Utility.log(header+" : "+con.getHeaderField(header)); @QvfN>T
else /;zZnF\e
break; 37%`P\O;s
} >|v=Ba6R0
} p Z0=
t^`<*H
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public void splitterStop() We[<BJo4
{ |3s.;wK
bStop = true; *K]>}
} eUX@9eML
C}x4#bNK
.a ~s_E
} 2q2p=H>&
e@='Q H
Z}]:x `fXd
/* pA*D/P-
**FileAccess.java zfk'>_'
*//文件访问(定位，写) =4YbVA+(
package NetFox; j:3A;r\
import java.io.*; ]$*$0
HY*l4QK
XMjI}SPG
public class FileAccessI implements Serializable{ p=:7 atE
d)`nxnbMeM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Yt\E/*%
RandomAccessFile oSavedFile; n,CD4Nv
long nPos; l=Lmr
-0=}|$H.
FCsyKdM
public FileAccessI() throws IOException wxdh?sQ
{ ,apd3X%g
this("",0); tXssejiE%
} $K=K?BV[
$#6Fnhh}
/ig^7+#
public FileAccessI(String sName,long nPos) throws IOException u!=]zW%
{ >=.ch5h3J)
oSavedFile = new RandomAccessFile(sName,"rw"); ?K= gg<
this.nPos = nPos; GM34-GH+
oSavedFile.seek(nPos); *Y|lO
} eukX#0/^
nOA,x
{|8:U}<#h
public synchronized int write(byte[] b,int nStart,int nLen) 5Ws:Ei{R
{ 842Mydom
int n = -1; E9~&f^f
try{ m? \#vw$
oSavedFile.write(b,nStart,nLen); Y/?DSo4G
n = nLen; (hD X4;4
} jgZX~D
catch(IOException e) :Su5
{ OF<[Nh\.
e.printStackTrace (); -y7l?N5F>
} ex;Yn{4
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LaAgoarN
return n; .HH,l
} S4@117z5
~|$) 1
MSxU>FX0
} xc3Ov9`8%
%j 9vX$Hj
W#oEF/G
/* ;DT"S{"7
**SiteInfoBean.java HbJadOK
*/ 8yJk81 gY
package NetFox; ;n:H6cp
|r<.R>
$w2[5|^S
public class SiteInfoBean { juve9HaW
Z(Ls#hp
Px^<2Q%Fs
private String sSiteURL; //Site's URL Yc|-sEK/
private String sFilePath; //Saved File's Path A61-AwvF8-
private String sFileName; //Saved File's Name *`\4j*$^
private int nSplitter; //Count of Splited Downloading File 0*]<RM
<9MQ
n]6w)wE(
public SiteInfoBean() gvwCoCbb
{//nSplitter的缺省值为5 U3VsMV*Y
//default value of nSplitter is 5 N?`GZ+5
this("","","",5); //4p1^%
} `"bRjC"f]
do:RPZ!
<try%p|f
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /ab K/8ZQ
{ E`sapk
sSiteURL= sURL; e2VL/>y`
sFilePath = sPath; l#J>It\
sFileName = sName; $D2Ain1
this.nSplitter = nSpiltter; *(XgUJq+
c+\Gd}IJq
QKL]O*
} QVA!z##
HjETinm"
J[_?>YJ
public String getSSiteURL() 4=#QN
{ E!(`275s
return sSiteURL; 'KN!m| z
} Xf'
@)M.u3{\
)9;kzp/
public void setSSiteURL(String value) 2Xk1AS
{ z<C~DH
sSiteURL = value; Vv*5{_
} rnt$BB[g
OkO@BWL
H603L|4
public String getSFilePath() 8)Bn?6.
{ ROI$;B(
return sFilePath; 4tN~UMw?
} "MVN/Gl
DQHGq_unP
T=)L5Vuq<
public void setSFilePath(String value) #7E&16Fk
{ H6+st`{
sFilePath = value; BRQ5
} )F9V=PJE
uma9yIk
F\$}8,9
public String getSFileName() C8%nBa/
{ $F==n4)
return sFileName; s13 d*
} rH9|JEz
{Ac3/UM/
h: (l+jr
public void setSFileName(String value) kv`3Y0R-"
{ R|^t~h-
sFileName = value; MJk:s[o
} ^<H#dkECG
<MDFfnj
c9TkIe
public int getNSplitter() >5YYij5Aj
{ s!zr>N"
return nSplitter; 1,sO =p)Yg
} _KlPbyLU
)Z`viT
.~/;v~bL
public void setNSplitter(int nCount) }N=zn7W
{ I5AjEp
nSplitter = nCount; jq]\oY8y
} ]{l O
} ;Q%19f3,6
ckkM)|kK
pRfHbPV?
/* Wn)A/Z ^r
**Utility.java .m % x-i
*/ 6(RqR
package NetFox; n$VPh/
enO=-#
Vf* B1Zb
public class Utility { ]4pC\0c
Y K62#;
kKTED1MW&W
public Utility() ;?[+vf")
{ E?W!.hbA
bu!<0AP"N+
[ZpG+VAJ8
} a~+WL
zK]%qv]
//线程睡眠 +vY`?k`
public static void sleep(int nSecond) KLM^O$=
{ I2!&="7@
try{ pPqbD}p
Thread.sleep(nSecond); hB1iSm
} 5nlyb,"^g
catch(Exception e) "Kf~`0P
{ AZm)$@e)
e.printStackTrace (); +/ d8d
} E~U|v'GCd
} ZtZV:re=
a[OLS+zf!P
//日志 A&|(%
public static void log(String sMsg) kT3;%D^
{ iY`7\/H!L
System.err.println(sMsg); =(uy':Dbn*
} 1 jd=R7
9U%}"uE
BJ;cF"Kp
public static void log(int sMsg) T%xL=STJNy
{ #SOj4W
System.err.println(sMsg); bSKV|z/x
} HGMH g
} <.]&FPJ
GoGgw]h>x
N1zrfn-VU
/* LWR&(p.%
**TestMethod.java -|UX}t*
*/ {ca^yHgGy
package NetFox; o".O#^3H%
~]s"PV:|
s~'C'B?
public class TestMethod { l3 Bc g
iK23`@&%_
ymJw{&^am
public TestMethod() \^Q)`Lqp:g
{ ///xx/weblogic60b2_win.exe 246!\zf
try{ mLdyt-1
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 3^Q U4
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 1T^L) %&p_
SiteFileFetch fileFetch = new SiteFileFetch(bean); " ~hjB
fileFetch.start(); H s 3*OhK\
} "!eT
catch(Exception e){e.printStackTrace ();} v[=E f
]qTr4`.
Q ?<9
} !q1^X% a
9O_N iu0
QE6-(/
public static void main(String[] args) --hnv/AjI
{ ?a_q!,8:
new TestMethod(); DFH6.0UW
} (9lx5
} > %*X2'^
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