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)); X7[^s $VK
} YNYx>Ue
for(int i=0;i<nEndPos.length-1;i++) og4UhP^UET
{ ?MXejEC
nEndPos = nStartPos[i+1]; .id)VF-l
} NxSu3e~PS
nEndPos[nEndPos.length-1] = nFileLength; +U_=*"@|
} *+'x~a
} Ny_lrfh)[
Z:ni$7<.
1[kMOp
//启动子线程 6cpw~
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^?$WVB
for(int i=0;i<nStartPos.length;i++) 0- ><q
{ pkP?i5,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), e'~Zo9`r6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 5'0xz.)!
nStartPos,nEndPos,i); X_qf"|i
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); g wz7krUTe
fileSplitterFetch.start(); rX*H)3F
} ;g6M%;1-
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *eIJwXE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); .R)PJc5^
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6)z?f4,
nEndPos = " + nFileLength); ]DZE%
// fileSplitterFetch[nPos.length-1].start(); xAafm<L@!
D*Ik7Pe
?aC'.jH+
//等待子线程结束 y[>;]R7'
//int count = 0; f?oa"
//是否结束while循环 ng:kA%! Q
boolean breakWhile = false; n$U#:aQE
"~=mG--I
IC6gU$e
while(!bStop) u583_k%
{ $k0kk
write_nPos(); pX/n)q[
Utility.sleep(500); zR `EU,
breakWhile = true; ~)qtply
qud\K+
GFfq+=se
for(int i=0;i<nStartPos.length;i++) o]Ol8I
{ D,;\o7V
if(!fileSplitterFetch.bDownOver) wtmB+:I
{ O_cbP59Y.
breakWhile = false; ?gJOgsHJP
break; \|]Z8t7
} uMut=ja(U
} DjI3?NN
if(breakWhile) \I["2C]3M
break; !1n8vzs"c
fR)m%m
<cZGxff01
//count++; k4,BNJt'Z
//if(count>4) ?6(I V]
// siteStop(); UJ0<%^f
} Dw=gs{8D
wUiys/OVM
3l[McZ
System.err.println("文件下载结束！"); ?notxE7 ]
} :[\v
catch(Exception e){e.printStackTrace ();} baJxU:Y=p
} W3Dc r@Dy
v$(lZa1
61/.K_%I.
//获得文件长度 LVc4CE f
public long getFileSize() O:TlIJwW
{ Q?8R[i
int nFileLength = -1; ^ "i l}8`
try{ @o#!EfZyE
URL url = new URL(siteInfoBean.getSSiteURL()); _9tK[/h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ebS0qo[oLH
httpConnection.setRequestProperty("User-Agent","NetFox"); IP``O!WP
(T>nPbv)
`6 /$M!4$
int responseCode=httpConnection.getResponseCode(); [01.\eh
if(responseCode>=400) '\Jj8oJQj
{ B.g[c97
processErrorCode(responseCode); y_*PQZ$c<
return -2; //-2 represent access is error #O$
} AX?fuDLs
I8+~ &V}
[cTe54n
String sHeader; %STliJ
%|^OOU}
)x}l3\s
for(int i=1;;i++) %{(x3\ *&
{ hX`hs-*qM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); o;W`4S^
//Utility.log(in.readLine()); $e\h}A6
sHeader=httpConnection.getHeaderFieldKey(i); 1z&Ly3
if(sHeader!=null) cTD!B% x
{ uC8L\UXk
if(sHeader.equals("Content-Length")) CbPuoOl
{ Oy<5>2^P
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "z0zpHXek
break; OkCQ?]
} =Zu^80/
} /n5F(5<
else %q!8={J8
break; T[,/5J
} U~} U\_
} HDda@Jy
catch(IOException e){e.printStackTrace ();} {fha`i
catch(Exception e){e.printStackTrace ();} p8kr/uMP ;
R)M_|ca
f6_];]yP
Utility.log(nFileLength); /;7y{(o
|J+(:{}~
!/^-;o7
return nFileLength; Sr&515
} -6tgsfEr
a-"k/P#
"V>R9dO{"!
//保存下载信息（文件指针位置） Cw~RJ^a_
private void write_nPos() uKz,SqX
{ i `s|,"0o
try{ H;U)b{
output = new DataOutputStream(new FileOutputStream(tmpFile)); c&X{dJWD
output.writeInt(nStartPos.length); o\88t){/kB
for(int i=0;i<nStartPos.length;i++) *[r!
{ L lw&& K
// output.writeLong(nPos); %/c+`Wd/l$
output.writeLong(fileSplitterFetch.nStartPos); b+6"#/s
output.writeLong(fileSplitterFetch.nEndPos); oEx\j+}@n
} ?Zc"C
output.close(); Rx*BwZ
} `%E8-]{uS
catch(IOException e){e.printStackTrace ();} X=6y_^
catch(Exception e){e.printStackTrace ();} P+!"wX0*N
} i]=&
EyI}{6~F
Ti2Ls5H}
//读取保存的下载信息（文件指针位置） `}m Q
private void read_nPos() JXixYwm
{ ~`GhS<D
try{ kdxz!
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); l"q1?kaVg
int nCount = input.readInt(); /erN;Oo%<
nStartPos = new long[nCount]; Dy]I8_
nEndPos = new long[nCount]; zF@o2<cD@
for(int i=0;i<nStartPos.length;i++) <W`#gn0b6
{ 4\pWB90V
nStartPos = input.readLong(); RP2_l$
nEndPos = input.readLong(); WpS1a440
} (faK+z,*6R
input.close(); YXU|h
} $B#6tk~u
catch(IOException e){e.printStackTrace ();} b1gaj"]
catch(Exception e){e.printStackTrace ();} \.f}W_OF
} G/d4f?RU
7_wJpTz
T"p(]@Ng
private void processErrorCode(int nErrorCode) l akp
{ yJsH=5A
System.err.println("Error Code : " + nErrorCode); &f>eQS=(
} l{:a1^[>y
j7MO'RX`&
Xt{*N-v\
//停止文件下载 3;7q`
public void siteStop() ]&ixhW
{ 7QVuc!V
bStop = true; Uz608u
for(int i=0;i<nStartPos.length;i++) O<jPGU
fileSplitterFetch.splitterStop(); {/LZcz[
ewuXpv%vwW
`gpQW~*R-;
} ExSO|g]%
} \ A%eG&
//负责部分文件的抓取 -/x W
**FileSplitterFetch.java uNHdpni
*/ !)qQbk
package NetFox; e8h,,:l3j
aup6?'G;
dI*'!wK
import java.io.*; DY{cQb
import java.net.*; 0G <hn8>
KtB!"yy#
Z?NEO>h7
public class FileSplitterFetch extends Thread { Nwc!r(
G~wFnl%
3Wcy)y>2Ap
String sURL; //File URL %d m-?`
long nStartPos; //File Snippet Start Position EPX8Wwf
long nEndPos; //File Snippet End Position 6al=Cwf
int nThreadID; //Thread's ID #.5vC5
boolean bDownOver = false; //Downing is over S'U@X
boolean bStop = false; //Stop identical zSv^<`X3
FileAccessI fileAccessI = null; //File Access interface tfkr+ /
a$9A(Pte
r7]"?#
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mxFn7.|r~
{ =q(GHg;'
this.sURL = sURL; 'R9g7,53R
this.nStartPos = nStart; maSgRf[g
this.nEndPos = nEnd; J^m<*
nThreadID = id; sT1&e5`W
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~vgA7E/XV
} 7OVbP%n)d2
I,ci >/+b
_2hXa!yO
public void run() k$Rnj`*^
{ ,WWj-X|+=
while(nStartPos < nEndPos && !bStop) ]lS@}W\
{ Q0_>'sEM
Ybg-"w
YCy22@C
try{ PoShQR<
URL url = new URL(sURL); t~M $%)h
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]Z4zF"@
httpConnection.setRequestProperty("User-Agent","NetFox"); R^MiP|?ZH
String sProperty = "bytes="+nStartPos+"-"; C+K=[
httpConnection.setRequestProperty("RANGE",sProperty); .G>t72DpU
Utility.log(sProperty); =y%rG :!
VY+>=!
!asqr1/
InputStream input = httpConnection.getInputStream(); 5IqQ|/m<6
//logResponseHead(httpConnection); ]M,06P>?
wk\L*\@Y}
%do1i W
byte[] b = new byte[1024]; h4fLl3%H
int nRead; pKJK9@Ad
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) LD(C\
{ V/"}ku
nStartPos += fileAccessI.write(b,0,nRead); TSL9ax4j
//if(nThreadID == 1) 7\/5r.
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 4p)e}W*
} $E(XjuS
_qWC4NMF(
Y:x/!-
Utility.log("Thread " + nThreadID + " is over!"); V*65b(q)
bDownOver = true; AxCI 0
//nPos = fileAccessI.write (b,0,nRead); PI|`vC|yy&
} *]s&8/Gmb
catch(Exception e){e.printStackTrace ();} ';RI7)<
} x:5dCI
} ?RD *1
. p^xS6e{
A8?[6^%O|
//打印回应的头信息 ^uaFg`S
public void logResponseHead(HttpURLConnection con) 0,FC YTtj$
{ Y?Vz(udD
for(int i=1;;i++) o;`!kIQ
{ QLbMPS
String header=con.getHeaderFieldKey(i); @qK<T
if(header!=null) ilEi")b=
//responseHeaders.put(header,httpConnection.getHeaderField(header)); b;9n'UX\
Utility.log(header+" : "+con.getHeaderField(header)); :kw0y
else O|v (58A
break; J\W-dI
} zTCP)x
} D\]&8w6&
5n:71$6[
,EhVSrh)_4
public void splitterStop() X<MpN5%|Wo
{ 6Dm+'y]l
bStop = true; :%_q[}e
} 73DlRt *
E`p'L!z
f =_^>>.
} a&/HSf_G
t&c&KFK)I&
rS~qi}4X
/* vC9@,[
**FileAccess.java Q5E:|)G
*//文件访问(定位，写) <jd/t19DB
package NetFox; hWGZd~L
import java.io.*; gOE_ ]
gM_:l
IUhp;iH
public class FileAccessI implements Serializable{ R40W'N1%q
G8NRj9k?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zg]Drm
RandomAccessFile oSavedFile; Hbr^vYs5
long nPos; ]G1R0 Q
mC(u2
hhq$g{+[
public FileAccessI() throws IOException rycJyiw<-
{ _Y YP4lEL
this("",0); mrnxI#6
} +Hy4s[_|
xw%)rm<t
GAJ~$AiwHH
public FileAccessI(String sName,long nPos) throws IOException P06.1
{ (Nt[v;BnO
oSavedFile = new RandomAccessFile(sName,"rw"); D=w9cKa
this.nPos = nPos; T0L+z/N_m.
oSavedFile.seek(nPos); A#:8X1w
} 5fq.*1f
my[,w$YM
8*k oxS
public synchronized int write(byte[] b,int nStart,int nLen) G^"H*a
{ ]IXAucI]
int n = -1; S1C^+Sla]
try{ j7sU0"7^
oSavedFile.write(b,nStart,nLen); OPJgIU%
n = nLen; C5B=NAc
} Dh8(HiXf:
catch(IOException e) 7ti<
{ ;l`X!3
e.printStackTrace (); lQr6;D}+
} -RCv7U`
m3%ef
LY1KQuY
return n; ftW{C1,U7
} +G\0L_B
z[FI2jl
9d] tjT
} T+BIy|O
![q}BU4
@fDQ^ 4
/* NV(fN-L
**SiteInfoBean.java R8{e&nPE
*/ o~}1oN
package NetFox; yr{5Rp05=
RR'(9QJ$
E~69^cd
public class SiteInfoBean { )ys=+Pz
p9w%kM?
(JvQ-H
private String sSiteURL; //Site's URL Z_jn27AC
private String sFilePath; //Saved File's Path .='3bQ(UZ4
private String sFileName; //Saved File's Name `&G}
private int nSplitter; //Count of Splited Downloading File !a)s`
$*aE$O6l
As p8qHS
public SiteInfoBean() J{^n=X9M0J
{//nSplitter的缺省值为5 iZu:uMoc
//default value of nSplitter is 5 lSs^A@s
this("","","",5); aC}vJ93i
} xtu]F
_H/67dcz,
J(&Gmk9&
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) S].Ft/+H
{ !}j,TPpG
sSiteURL= sURL; ax;{MfsK
sFilePath = sPath; T!&jFy*W
sFileName = sName; ->Q`'@'|P
this.nSplitter = nSpiltter; 7rJ9 }/<I
[ArO$X3\
(,d/JnP
} #EEG>M*xB
s|BX>1
Y)5)s0}
public String getSSiteURL() rt,0j/o.1
{ ^$8Vh=D
return sSiteURL; `Q+i-y
} >9(7h&[Y
A&;EV#]ge
Y]M^n&f
public void setSSiteURL(String value) ;*"!:GR%h
{ ''%;EW>
sSiteURL = value; T^+1rG
} q!9^#c
@OBHAoz%/
J]$er0`LY
public String getSFilePath() KuU3DTS85Z
{ .wM:YX'[G
return sFilePath; !k%l+I3J[
} Gmqs`{tc
kf}F}Ad:%
A>J1B(up
public void setSFilePath(String value) o- cj&Cv%
{ X9DM^tt
sFilePath = value; ?'TA!MR
} XTIu(f|d_;
J&n ^y
9$:QLE+t
public String getSFileName() -MQZiq7H4
{ B-B?Ff>
return sFileName; g"TPII$
} 8x!+tw7
:~WPY9i`
],H1
public void setSFileName(String value) NW}>pb9
{ #>MO]
sFileName = value; h85(N
} AB/,S
FGV}5L
',L{CQA?c
public int getNSplitter() C+X)">/+L
{ 2Px$0&VN
return nSplitter; XhQw+j~1.
} z"G`o"4 V
NvEm,E\|
}C_G0'"F
public void setNSplitter(int nCount) }R7sj
{ \.K\YAM<
nSplitter = nCount; Wg}B@:`T
} =}B4I
} P@^z:RS*{
~uP r]#
D2>hMc
/* 4.,KEt'H
**Utility.java <K=@-4/Bp
*/ Eqz4{\
package NetFox; (#!(Q) ]
Pmqx ;
n25irCD`
public class Utility { ORV}j,Ym
V%X:1 8j
<^H1)=tlF
public Utility() BfD,z
{ \O8Y3|<
?Zc/upd:$N
>reaIBT
} BFzcoBu-
$[HcHnf
//线程睡眠 p?J~'
public static void sleep(int nSecond) t(Q&H!~e
{ B[) [fE
try{ VEFwqB1l
Thread.sleep(nSecond); bLU^1S8Z
} FYx `o\
catch(Exception e) ~zXG<}n
{ [4K9|/J
e.printStackTrace (); <3i4NXnL2
} I_"Hgx<
} e>])m3xvn
rW=k%# p
//日志 hQd@bN8
public static void log(String sMsg) }}4sh5z
{ 4yJ*85e]
System.err.println(sMsg); CjC'"+[w
} $UFge%`,q@
RTgQ#<W8
= )JVT$]w
public static void log(int sMsg) yr/]xc$
{ vp )}/&/
System.err.println(sMsg); Y|GJph
} |Ak =-.
} 4~m.#6MT
cu.*4zs
4Vb}i[</
/* 6b#:H~ <
**TestMethod.java zkT`] @`J
*/ /ZIJ<#o[
package NetFox; Q`@$j,v
TQOg~lH
S:2u3th7
public class TestMethod { `uM0,Z
6)uPM"cO
KG4#BY&^
public TestMethod() CN8@c!mB
{ ///xx/weblogic60b2_win.exe 3$96+A^M*
try{ )JY_eG&2Dx
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); (dLE<\E
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Cu ['&_@
SiteFileFetch fileFetch = new SiteFileFetch(bean); +qh< Fj>
fileFetch.start(); !BvTJ-e)F
} ,E/Y@sajn+
catch(Exception e){e.printStackTrace ();} r{/ G\
LEn=dU
O$<%z[
} aUIc=Z
#TW>'lF
<y\ Z#z
public static void main(String[] args) Y?&DEKFbD
{ &0th1-OP_
new TestMethod(); 4mM2C`I
} YvxMA#
} d0H
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