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)); &fyT}MA
} xE[CNJ%t^,
for(int i=0;i<nEndPos.length-1;i++) |i}5vT78
{ _ ?\4k{ET
nEndPos = nStartPos[i+1]; ;RmL'
} rA"><pH
nEndPos[nEndPos.length-1] = nFileLength; PB W.nm
} ug|'}\LY
} }'"4q
v0d<P2ix
C6!P8qX
//启动子线程 Q#,j,h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; #fuc`X3:HL
for(int i=0;i<nStartPos.length;i++) >z,SN
{ 6F@2:]W
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {m<NPtp910
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), m^9[k,;K
nStartPos,nEndPos,i); [pc6!qhDG&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); W@T_-pTCjK
fileSplitterFetch.start(); 7[b]%i
} m9&MTRD\
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #VLO6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); RfZZqeU
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", G;'=#c ^
nEndPos = " + nFileLength); _(TYR*
// fileSplitterFetch[nPos.length-1].start(); SviGLv;oR
#nzVgV]
.Lvg $d
//等待子线程结束 " iKX-VIl
//int count = 0; TqZ&X|G
//是否结束while循环 ,rO>5$w.
boolean breakWhile = false; jgkJF[t`
#Q6.r.3@x
cc$L56q
while(!bStop) W,g0n=2V
{ HZG<aY="
write_nPos(); .t7mTpi
Utility.sleep(500); !Q0aKkMfL
breakWhile = true; '(qVA>S
,o_Ur.UJ
Py3Y*YP
for(int i=0;i<nStartPos.length;i++) 0VA$ Ige
{ uPp9 UW
if(!fileSplitterFetch.bDownOver) +pq/:h
{ 2f=7`1RCD
breakWhile = false; Y(`# J[
break; V&j |St[
} /=|5YxY
} %)|_&Rh
if(breakWhile) qM|-2Zl!+
break; cSkJlhwNn
}'FNGn.~#
r2Wx31j{
//count++; }IRx$cKV
//if(count>4) hZudVBn
// siteStop(); +(*;F4>
} itp$c|{
:Hn*|+'
^LO`6,
System.err.println("文件下载结束！"); \k8|3Y~g
} 9qqzCMrI0e
catch(Exception e){e.printStackTrace ();} d- wbZ)BR
} &>0ape
+mr\AAFn
@`hnp:
//获得文件长度 @ZD/y%e
public long getFileSize() T9c=As_EM
{ n1Y3b~E?E
int nFileLength = -1; UT^-!L LB]
try{ )/:r$n7
URL url = new URL(siteInfoBean.getSSiteURL()); @ k`^Z5tN
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Dn}Wsd=
httpConnection.setRequestProperty("User-Agent","NetFox"); !JkH$~
X+:>&&9
X~H~k1
int responseCode=httpConnection.getResponseCode(); 77:s=)
if(responseCode>=400) TC2gl[
{ v7L}I[f
processErrorCode(responseCode); K~?M?sa
return -2; //-2 represent access is error Tt0:rQ.
} |&>!"27;w
'+ 8.nN
@k~_ w#
String sHeader; frYPC Irj
6]#\|lds1
!A6l\_
for(int i=1;;i++) c1,dT2:=
{ !Gphs`YI
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); s`bC?wr5h
//Utility.log(in.readLine()); A(xCW+h@)
sHeader=httpConnection.getHeaderFieldKey(i); (4U59<ie
if(sHeader!=null) Ix"hl0Kh
{ )ZU=`!4
if(sHeader.equals("Content-Length")) L 1fK
{ V?k"BU
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); %/^kr ZD
break; Xgy)Z:R
} s 4Mi9h_
} 05|,-S
else wc-ll&0Z
break; qlUw;{;p
} 7jb{E+DrG
} &I[ITp6y0
catch(IOException e){e.printStackTrace ();} Qe~2'Hw#9
catch(Exception e){e.printStackTrace ();} Qoj}]jve
8Jz/'
a-`OE"
Utility.log(nFileLength); .45XS>=z#
cI5*`LML1
#&@qmps(T
return nFileLength; O$><E8q
} t*fG;YOg
+3c!.] o;
x bG'![OX
//保存下载信息（文件指针位置） %Jrdr`<
private void write_nPos() NMSpi[dr
{ a=55bEn
try{ '.@'^80iQ
output = new DataOutputStream(new FileOutputStream(tmpFile)); 3b_tK^|'
output.writeInt(nStartPos.length); iw,F)O
for(int i=0;i<nStartPos.length;i++) {(DD~~)D
{ 3wS{@'
// output.writeLong(nPos); ! Z e
output.writeLong(fileSplitterFetch.nStartPos); S;o U'KOY
output.writeLong(fileSplitterFetch.nEndPos); )$#r6fQO
} dh7PpuN{
output.close(); _HT*>-B
} 0I.9m[<Fc
catch(IOException e){e.printStackTrace ();} 3X+uJb2
catch(Exception e){e.printStackTrace ();} !Q,A#N(
} S=Ihg
@~!1wPvF`I
a<.7q1F
//读取保存的下载信息（文件指针位置） >.D0McQg
private void read_nPos() ;w(]z
{ + *YGsM`E9
try{ BO5gwvyI
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); %j].' ;
int nCount = input.readInt(); QK5y%bTSA
nStartPos = new long[nCount]; 728}K^7:
nEndPos = new long[nCount]; 2$D *~~
for(int i=0;i<nStartPos.length;i++) 5G~;g
{ eQk ~YA]K
nStartPos = input.readLong(); fwy-M:
nEndPos = input.readLong(); 8ycmvpJ
} 26fm}QV
input.close(); Fr%LV#Q
} &`a$n2ycy
catch(IOException e){e.printStackTrace ();} W|U!kqU
catch(Exception e){e.printStackTrace ();} h(,SAY_
} hT&,5zaWdv
(D'Z4Y
wz*QB6QtU
private void processErrorCode(int nErrorCode) 2a;vLc4
{ i^{.Q-
System.err.println("Error Code : " + nErrorCode); c<V.\y0x
} r<;bArs-u
W{OlJRX8
{IeW~S'&
//停止文件下载 .+G),P)
public void siteStop() U*ZP>Vv
{ qO
bStop = true; ]P TTI\n
for(int i=0;i<nStartPos.length;i++) PN{l)&K2.
fileSplitterFetch.splitterStop(); u7u8cVF
l`2X'sw[/
I/bED~Z:a
} 9=&e5Oq}
} QZBXI3%#s
//负责部分文件的抓取 Sf}>~z2
**FileSplitterFetch.java |Xblz1>DF
*/ IMY?L
package NetFox; d7A08l{
gmfux b/
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import java.io.*; -ob_]CKtJ~
import java.net.*; ZdEeY|j
a1p:~;f}[
DBl.bgf
public class FileSplitterFetch extends Thread { 0fvQPs!O
,P^pDrc
Z*d8b
String sURL; //File URL #&.&Uu$
long nStartPos; //File Snippet Start Position d:0RDK-}s
long nEndPos; //File Snippet End Position 2}u hPW+
int nThreadID; //Thread's ID Fzk
boolean bDownOver = false; //Downing is over Y[gj2vNe4g
boolean bStop = false; //Stop identical ?JTy+V2t
FileAccessI fileAccessI = null; //File Access interface f>JuxX\G
pN<wO1\9
lgZ3=h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException )5lo^Qb
{ b=a&!r5M
this.sURL = sURL; xm>RLx}9
this.nStartPos = nStart; DCb\=E
this.nEndPos = nEnd; ze Qgg|;
nThreadID = id; c,KT1me
fileAccessI = new FileAccessI(sName,nStartPos);//定位 YzU(U_g$
} ;YxQo o>
&I.UEF2,
mt7}1s,i[
public void run() /%Bc*k=ox
{ sk!v!^\_r
while(nStartPos < nEndPos && !bStop) Wy%q9x]}
{ QP|Ou*Qm)
B^Q\l!r
zIWw055W
try{ SsDz>PP
URL url = new URL(sURL); RqW ZhHI1M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Q7$ILW-S
httpConnection.setRequestProperty("User-Agent","NetFox"); N<+ ><>9
String sProperty = "bytes="+nStartPos+"-"; %4U;Rdq&Ud
httpConnection.setRequestProperty("RANGE",sProperty); vm)&WEL!
Utility.log(sProperty); ?eT^gWX
]#N2:ych
~$>l@> xX
InputStream input = httpConnection.getInputStream(); 9^J8V]X
//logResponseHead(httpConnection); 80cBLGG
~C< X~$y&
WO$PW`k
byte[] b = new byte[1024]; @L^2VVWk^
int nRead; ^Sx0t
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) < pI2}
{ _3h(R`VdWO
nStartPos += fileAccessI.write(b,0,nRead); cTmoz.0
//if(nThreadID == 1) JwbC3t):@
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); xA]CtB*o7
} |@={:gRJ{x
-UkP{x)S
>z6(fM`i
Utility.log("Thread " + nThreadID + " is over!"); `h12
bDownOver = true; {zBf*x
//nPos = fileAccessI.write (b,0,nRead); r00waw>C\
} C$\|eC j
catch(Exception e){e.printStackTrace ();} <OF7:f
} o:_}=1nh
} s S8Z5k;
km'3[}8o&
S2K_>kvG)~
//打印回应的头信息 ^AMcZ6!\
public void logResponseHead(HttpURLConnection con) qSj2=dlW
{ _*6nTSL
for(int i=1;;i++) r_T\%
{ }% JLwN
String header=con.getHeaderFieldKey(i); vrdlI^
if(header!=null) ,"
//responseHeaders.put(header,httpConnection.getHeaderField(header)); jdQ`Y+BC
Utility.log(header+" : "+con.getHeaderField(header)); -,Cx|Nl
else 9_[TYzpB!
break; }6.R.*Imz
} :kqJ~
} npg.*I/>
on $?c
|\2zw _o
public void splitterStop() /ZZo`
{ 33|>u+
bStop = true; OBi9aFoQ
} _)Q)tOW
(=0W[@k
2}>jq8Y47
} rH8^Fl&jT
`GS!$9j
;oVdkp
/* ,rc5r3
**FileAccess.java y.2_5&e/
*//文件访问(定位，写) +:?-Xd:p
package NetFox; DCM,|FE
import java.io.*; @Z~lM5n$8
BKfcK>%g
{<iIL3\mC
public class FileAccessI implements Serializable{ :j9{n ,F
[Rw0']i`4
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Ek(. ["
RandomAccessFile oSavedFile; FGu:8`c9
long nPos; $n& alcU
Jf@M>BT^A
$[5ihV$u
public FileAccessI() throws IOException y7dnXO!g9-
{ 2]5dSXD
this("",0); [jve |-v=
} w-};\]I
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2Ch!LS:+
public FileAccessI(String sName,long nPos) throws IOException g !w7Yv
{ X|t?{.p
oSavedFile = new RandomAccessFile(sName,"rw"); h<\o[n7j
this.nPos = nPos; mm\Jf
oSavedFile.seek(nPos); `o yz"07m
} ct=|y(_
7(^<Z5@
G!T)V2y
public synchronized int write(byte[] b,int nStart,int nLen) zg2A$Fd[j
{ Oyhl*`-*t
int n = -1; [>::@[
try{ _,_>B8
oSavedFile.write(b,nStart,nLen); pa Uh+"y>
n = nLen; F.ryeOJ
} PcC9)x
catch(IOException e) p>h B&h
{ DtG><g}[]
e.printStackTrace (); Fh9`8
} ~Y@(
e4u$+
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return n; >/nS<y>
} VS@o_fUx)
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Lw\ANku
} "12.Bi.O"[
@4Z>;
$Ll]h</Z
/* e5maZ(.;F
**SiteInfoBean.java ,,S5 8\x
*/ 'W usEME
package NetFox; sh[Yu
\Xc6K!HJM
{EGiGwpf
public class SiteInfoBean { %ribxgmd
, fFB.q"
\ F#mwl,>"
private String sSiteURL; //Site's URL Xg?hh 0s
private String sFilePath; //Saved File's Path .9+"rK}u
private String sFileName; //Saved File's Name k-xh-&
private int nSplitter; //Count of Splited Downloading File RoSh|$JF
o1YX^-<[F
'x{g P?.
public SiteInfoBean() <iunDL0
{//nSplitter的缺省值为5 n(l!T 7
//default value of nSplitter is 5 G<OC99;8
this("","","",5); 1VL!0H
} ~'KymarPU
LOpnPH`
qEPvV
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) yjvzA|(YC
{ 6 /gh_'&
sSiteURL= sURL; p#hs8xz
sFilePath = sPath; &!]$#
sFileName = sName; %&5 !vK
this.nSplitter = nSpiltter; @B %m,Mx
`4__X;
P66{l^
} !ccKbw)J#
Re-~C[zwT
DZ5%-
public String getSSiteURL() <at/z9b
{ f@l$52f3D
return sSiteURL; z(d@!Cd
} >J^bs &j
0? (
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public void setSSiteURL(String value) -v.\CtpHv
{ V.#,dDC@j
sSiteURL = value; Ls)y.u
} l-xKfp`
b|U&{I>TH
zJWBovT/
public String getSFilePath() Kj,C9
{ h!ZEZ|{
return sFilePath; EGL1[7It`
} ojU:RRr4l$
~Z!!wDHS
3US}('
public void setSFilePath(String value) exrsYo!%
{ -FV$Sne
sFilePath = value; L ?g|:
} *`OgwMr)M
$7eO33Bm
i71,
public String getSFileName() hX?L/yf
{ g^@Kx5O\
return sFileName; #3vq+mcn
} Og[NRd+
jOj`S%7
7yo/sb9h
public void setSFileName(String value) ,o7aIg&_H
{ tgK$}#.*
sFileName = value; uSCF;y=1g,
} QEK,mc3
0KO_bF#EB=
*c4uCI:0t
public int getNSplitter() gQ4Q h;
{ HMGby2^+
return nSplitter; ;SoKX?up5
} }VxbO8\b(
P3V=DOG"
BV,P;T0"D
public void setNSplitter(int nCount) L&M6s f$N
{ )k@W6N
nSplitter = nCount; /Y@^B,6\
} yep`~``_
} DqyJ]}|
. [DCL
/3->TS
/* _yY(&(]#
**Utility.java XlIRedZ{
*/ .r[b!o^VR
package NetFox; 6}wXNTd
H~E(~fl
T.O^40y
public class Utility { ',j'Hf
wr{03mQHxp
f>\OT
public Utility() w='1uV<6
{ ktLXL;~X
T)wc{C9w
0Ci\(
} 5Nc~cD%0tK
M,@\*qlEJ
//线程睡眠 {;0j9rr
public static void sleep(int nSecond) 'WK}T)o
{ Qb}7lm{r
try{ %"^$$$6%
Thread.sleep(nSecond); }rf_:
} tn\Y:
catch(Exception e) a$ a+3}\
{ )R$+dPu>
e.printStackTrace (); 7uG@hL36
} #PUvrA2Zl
} dA>=#/"
A5-y+
//日志 OJ8ac6cJ
public static void log(String sMsg) F{}mlQg
{ iTsmUq<b]l
System.err.println(sMsg); Qj: D=j8
} RG/M-
h- .V[]<
3qOq:ZkQ
public static void log(int sMsg) ~$XbYR-
{ _[;>V*?zp5
System.err.println(sMsg); <>$`vuU
} .,zrr&Po
} yoa"21E$
xLX<.z!r
58\rl G
/* v#*9rNEj0
**TestMethod.java lJ.:5$2H
*/ 'Lu7cb^
package NetFox; <>/0;J1<
IJHNb_Cku
@ hH;d\W#
public class TestMethod { 2[f8"'lUQ
?dMyhU}
z{:T~s
public TestMethod() P#-9{T
{ ///xx/weblogic60b2_win.exe ZN>oz@jY
try{ GJz d4kj
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7=C$*)x
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *izPLM}+
SiteFileFetch fileFetch = new SiteFileFetch(bean); K6<@DP+/
fileFetch.start(); y1R53u`;L
} K{)N:|y%!$
catch(Exception e){e.printStackTrace ();} 1}+lL)-!
5&a4c"fU
M{I8b<hY
} ipU,.@~#
SA_5..
=au7'i|6
public static void main(String[] args) kBolDPvBG
{ 0'y9HE'e
new TestMethod(); ufF$7@(+
} OZ 4uk.)
} xGsg'
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