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)); <Dk6o`7^N
} to,\sc
for(int i=0;i<nEndPos.length-1;i++) 0^('hS&
{ omu)s '8
nEndPos = nStartPos[i+1]; xu<oQBt
} \0fS;Q^{j
nEndPos[nEndPos.length-1] = nFileLength; 15J t @{<r
} vCX 54
} 0]k-0#JM
X:2)C-l?
&9OnN<mT1
//启动子线程 jCp^CNbA
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;M<R e
for(int i=0;i<nStartPos.length;i++) 3sD/4 ?
{ nVyV]'-z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nG4}8
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,II-:&H
nStartPos,nEndPos,i); *G&3NSM-
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2H,n"-9+
fileSplitterFetch.start(); !-AK@`i.
} *e,GXU@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), {ovW6#
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); i+@t_pxc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", %LjhK,'h
nEndPos = " + nFileLength); \%/Y(YVm
// fileSplitterFetch[nPos.length-1].start(); &"6%D|Z0
+bdjZD3
L)"E_
//等待子线程结束 FE'F@aS\
//int count = 0; 1|XC$0
//是否结束while循环 |SX31T9rG
boolean breakWhile = false; RLNto5?
Vw";< <0HZ
p>h&SD?b
while(!bStop) ;%^T*?t
{ Jp 7m$D%
write_nPos(); i87+9X
Utility.sleep(500); W&=F<n`
breakWhile = true; ab8F\%y-8
;d<RPVE:
sjj,q?
for(int i=0;i<nStartPos.length;i++) I?OnEw
{ W[B;;"ro
if(!fileSplitterFetch.bDownOver) R>B4v+b
{ `xsU'Wd^<
breakWhile = false; *pSD[E>SU
break; AQgagE^
} z8JdA%YBM
} j|owU
if(breakWhile) \O=t5yS
break; }@TtX\7(D
>Pwu>
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//count++; P$i d?
//if(count>4) w,VUWja
// siteStop(); 1kczlTF
} d>hLnz1O
krecUpo
i p; RlO
System.err.println("文件下载结束！"); ^3lEfI<pBm
} !Ct'H1J-
catch(Exception e){e.printStackTrace ();} 94'0X
} D:#e;K
' }T6dS
wvz_)bN~A
//获得文件长度 + 0 |d2_]E
public long getFileSize() a&C}'e"
{ &O\$=&, h
int nFileLength = -1; JW9U&Bj{
try{ &Xp<%[:
URL url = new URL(siteInfoBean.getSSiteURL()); NsF8`rg
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9-hVlQ~|
httpConnection.setRequestProperty("User-Agent","NetFox"); !g7bkA
wq>0W4(
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int responseCode=httpConnection.getResponseCode(); &Ef_p-e-P
if(responseCode>=400) #G\;)pT
{ Np2.X+
processErrorCode(responseCode); E3d# T
return -2; //-2 represent access is error AfXlV-v
} (0!U,8zz
L@x#:s=
&uLC{Ik}
String sHeader; dS)c~:&+
K!qV82b='{
i1ss}JJp*
for(int i=1;;i++) n]a/nv
{ w6G<&1iH
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); VjGtEIew
//Utility.log(in.readLine()); <?Y.w1
sHeader=httpConnection.getHeaderFieldKey(i); xa?
if(sHeader!=null) 0=I:VGC3
{ s\io9'Ec
if(sHeader.equals("Content-Length")) &? z6f9*$
{ p^X \~Yibs
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); R6E.C!EI
break; W?2Z31;7
} /2fQM_ ,P
} bFwc>
else 5o2|QL
break; ,%U'>F?
} ,_!MI+o0
} Xw]L'+V=
catch(IOException e){e.printStackTrace ();} .TKKjS%8
catch(Exception e){e.printStackTrace ();} `%Jq^uW
HK4 *+
0})mCVBY
Utility.log(nFileLength); s*UO!bHa
Y4,LXuQ
CSNfLGA
return nFileLength; Uv%?z0F<C
} 3!2TE-
xAJuIR1Hi
E;Q ,{{#
//保存下载信息（文件指针位置） b&xlT+GN
private void write_nPos() D&nVkZP>
{ K[M[0D
try{ IrTMZG
output = new DataOutputStream(new FileOutputStream(tmpFile)); +/Qgl
output.writeInt(nStartPos.length); ?0hEd9TU
for(int i=0;i<nStartPos.length;i++) 9MR,3/&N
{ Mhiz{Td
// output.writeLong(nPos); ~-zch=+u
output.writeLong(fileSplitterFetch.nStartPos); V^E.9fs,
output.writeLong(fileSplitterFetch.nEndPos); wC>Xu.Z:
} |z]--h
output.close(); $i.)1.x
} HRF;qR9v
catch(IOException e){e.printStackTrace ();} KSB{Z TE
catch(Exception e){e.printStackTrace ();} qJq2Z.>hy
} .vk|aIG
az;o7[rI^
5$Da\?Fpn
//读取保存的下载信息（文件指针位置） V>:ubl8j0l
private void read_nPos() -Gn0TA2/C
{ mrId`<L5l{
try{ AD4Ot5
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); *Rj(~Q/t
int nCount = input.readInt(); !/wR[`s9w
nStartPos = new long[nCount]; E'wJ+X9 +
nEndPos = new long[nCount]; :y8wv|m
for(int i=0;i<nStartPos.length;i++) TYN~c(
{ jw$[b=sa
nStartPos = input.readLong(); w//L2.
nEndPos = input.readLong(); gbL!8Z1h
} LS{t7P9K
input.close(); @-G^Jm9~\m
} GEQ3r'B|
catch(IOException e){e.printStackTrace ();} $9Asr07
catch(Exception e){e.printStackTrace ();} F2Nb]f
} cgF?[Z+x
3|9 U`@
b@m\ca
private void processErrorCode(int nErrorCode) t-3y`31i.
{ U6 $)e.FO
System.err.println("Error Code : " + nErrorCode); _5JwJcQ
} i!DO
kCVA~%d7
<yz&> +9,
//停止文件下载 +c-?1j
public void siteStop() B?p18u$i#l
{ Yk!TQY4
bStop = true; / +9o?Kxya
for(int i=0;i<nStartPos.length;i++) Z+]Uw
fileSplitterFetch.splitterStop(); SxWK@)tP
[(PD2GO+
L2 ^-t7
} w0!4@
} E[E7GsmqV
//负责部分文件的抓取 W&Pp5KR
**FileSplitterFetch.java ,sln0
*/ o:8*WCiqrN
package NetFox; Qkq9oZ
.uwD;j +#
!i77v, (#|
import java.io.*; +8~C&K:
import java.net.*; 4g}'/
dyNKok#
qmWn$,ax
public class FileSplitterFetch extends Thread { NQ"`F,T
bUBQ
*oca
String sURL; //File URL [d}AlG!
long nStartPos; //File Snippet Start Position r[Zg$CW
long nEndPos; //File Snippet End Position w!N?:}P<N
int nThreadID; //Thread's ID F,'rW:{HMt
boolean bDownOver = false; //Downing is over 1@L|EFa
boolean bStop = false; //Stop identical :d,]BB
FileAccessI fileAccessI = null; //File Access interface JLFZy\
qTD^Vz V
]31UA>/TI
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Z<^TO1xs9B
{ 67{>x[
this.sURL = sURL; eg$y,Tx
this.nStartPos = nStart; `7mRUDz
this.nEndPos = nEnd; k}h\RCy%f
nThreadID = id; g&oAa;~o
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ;R x Rap
} r}]%(D](v
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~.H*"
public void run() |A0)-sVZ
{ 8BgHoQ*
while(nStartPos < nEndPos && !bStop) '|JBA.s|
{ 1{pU:/_W
#y:,owo3I
m_pqU(sP
try{ -IF3'VG
URL url = new URL(sURL); dqu+-43I|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); yl'@p5n
httpConnection.setRequestProperty("User-Agent","NetFox"); (yB)rBh>n
String sProperty = "bytes="+nStartPos+"-"; xG|T_|?
httpConnection.setRequestProperty("RANGE",sProperty); J jp)%c#_
Utility.log(sProperty); yv2N5IQ>{V
quGvq"Y>
ejjL>'G/|%
InputStream input = httpConnection.getInputStream(); 1#m'u5L
//logResponseHead(httpConnection); B=p6pf
q}'ww
mtunD;_Dek
byte[] b = new byte[1024]; ]:X# w0UR
int nRead; <*'%Xgm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) $wBF'|eU
{ ~Y.I;EPKt
nStartPos += fileAccessI.write(b,0,nRead); _>k&M7OU4
//if(nThreadID == 1) ?0%3~E`l:
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 1O{(9nNj
} 8uZM%7kI6+
fKYRDGn
4,)EG1
Utility.log("Thread " + nThreadID + " is over!"); O7of9F~"
bDownOver = true; !um~P
//nPos = fileAccessI.write (b,0,nRead); b2<((H
} P56B~M_
catch(Exception e){e.printStackTrace ();} _9<nM48+t
} 2b i:Q9
} l}jC$B`5
yJRqX]MLA
6#SUfK;
//打印回应的头信息 >nqCUhS
public void logResponseHead(HttpURLConnection con) iS]4F_|vd
{ jr`;H
for(int i=1;;i++) U-mZO7y!
{ YooPHeQ
String header=con.getHeaderFieldKey(i); Vhi4_~W3j]
if(header!=null) DY(pU/q
//responseHeaders.put(header,httpConnection.getHeaderField(header)); h%*@82DKK
Utility.log(header+" : "+con.getHeaderField(header)); (Q4hm]<
else XGCjB{IV
break; }8e_
} j'QPJ(`~1l
} K}j["p<!
aB*'DDlx"r
wdo(K.m
public void splitterStop() 99G'`NO
{ gL(_!mcwu
bStop = true; :H(wW
} Q dPqcw4+X
J\%SAit@
JOUZ"^v
} ALY3en9,
L#6!W
<<M1:1
/* .X](B~\!
**FileAccess.java ]H$Trf:L
*//文件访问(定位，写) L}M%z9K`h
package NetFox; h%UM<TZ]"
import java.io.*; qe<xH#6
6F8TiR&
^(+@uuBx
public class FileAccessI implements Serializable{ /:.p{y
rf=oH }
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 bHK[Z5
RandomAccessFile oSavedFile; h2P&<ggqX
long nPos; zb,YYE1
k((kx:
GvTA/zA
public FileAccessI() throws IOException Min{&?a
{ >Hwf/Gf[
this("",0); *ORa@x
} u/.# zn@9h
x,j%3/J^2
8JojKH
public FileAccessI(String sName,long nPos) throws IOException 'NN3XyD
{ nkkUby9
oSavedFile = new RandomAccessFile(sName,"rw"); i;<K)5Z
this.nPos = nPos; ,veo/k<"r8
oSavedFile.seek(nPos); Eyh(257
} T~naAP
I#-T/1N
p]Q(Z
public synchronized int write(byte[] b,int nStart,int nLen) BYZllwxwTE
{ (Eo#oX
int n = -1; ]ZS/9 $
try{ _Kv;hR>
oSavedFile.write(b,nStart,nLen); I@uin|X
n = nLen; [(iJj3s!
} kj@m5`G
catch(IOException e) DIWcX<s
{ J\Z\q
e.printStackTrace (); vqRW^>~-B
} NBO&VYs|
;|.IUXEgcF
18JAca8Zs
return n; }^ZPah
} Y4)=D@JI
cxxrvP-
D1~3 3;
} |\/V1
aWMEo`O%
F2CoXe7
/* gro@+^DmT
**SiteInfoBean.java K2ry@haN
*/ u =|A
package NetFox; _.BX#BIF
/;xmM2B'
QW6\~l 4
public class SiteInfoBean { QiQO>r
-\~D6OA
j~`rc2n%
private String sSiteURL; //Site's URL KHt.g`1:R
private String sFilePath; //Saved File's Path J2Eb"y>/;
private String sFileName; //Saved File's Name M\jTeB"Z
private int nSplitter; //Count of Splited Downloading File H8?Kgaj~vf
uNG?`>4>
s(M8 Y
public SiteInfoBean() I:,D:00+
{//nSplitter的缺省值为5 @M]7',2"
//default value of nSplitter is 5 i*Ee(m]I
this("","","",5); U#1,]a\
} d=8q/]_p
e$y VV#
pm}!?TL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Oa|'wh ug
{ y}!}*Qj+/
sSiteURL= sURL; }dO^q-t$3
sFilePath = sPath; RE}$(T=
sFileName = sName; -P|st;?#
this.nSplitter = nSpiltter; l-RwCw4f
mo- Y %
$E]WU?U
} %#,EqN
XB'PEvh8
Wa+q[E
public String getSSiteURL() )Y}8)/Pud
{ x)Ls(Xh+g
return sSiteURL; v\:P_J
} _}(ej&'f
e4/Y/:vFO
]~1Xx:X-
public void setSSiteURL(String value) PhOtSml0
{ L\Y4$e9bF8
sSiteURL = value; w `0m[*
} "`4V^1
&KS*rHgt?
3/q)%Z^=
public String getSFilePath() p 3*y8g-
{ 1fzHmD
return sFilePath; rr=e
} cq,0?2R`t
=~f\m:Y
CFU'- #b
public void setSFilePath(String value) A\v(!yg
{ qu:nV"~_
sFilePath = value; chF@',9t
} n$O[yRMI[
2)zAX"#/
[R~`6
public String getSFileName() .!pr0/9B
{ NP#:} )
return sFileName; ^Voi4;
} TppuEC>
6*\WH%
yHk}'YP
public void setSFileName(String value) ZcLW8L
{ RU_wr<
sFileName = value; W1T% Q88
} -FGQn |h4
d~F4
t) :'XGk@
public int getNSplitter() Jb (CH4|7
{ &Q`{ Gk
return nSplitter; {%b*4x0?
} +338z<'Z!
qG<3H!Z!ky
y k{8O.g
public void setNSplitter(int nCount) s9)U",
{ 7a_tT;f;
nSplitter = nCount; $,)PO Z
} &{uj3s&C
} Na$eeM
iX|K4.Pz{
{)?:d6"
/* }83a^E9L
**Utility.java js..k*j
*/ a7@':Rb n
package NetFox; qbsmB8rh
rV_i|
J_S8=`f%
public class Utility { J6[V7R[\
/f}!G
[`4
public Utility() xk*&zAt
{ $Vp*,oRL
ZO#f)>s2
#=g1V?D
} RH}i=
[p+-]V
//线程睡眠 o"!C8s_6
public static void sleep(int nSecond) 9$?Sts}6&
{ akA7))Q
try{ n "bii7h
Thread.sleep(nSecond); ?Qxf~,F
} 7,lnfCm H
catch(Exception e) ;l %$-/%
{ lz7?Z
e.printStackTrace (); 64i*_\UKe
} 21$E.x 6
} `FGYc
KTq+JT u
//日志 OUk"aAo
public static void log(String sMsg) 8<)ZpB,7
{ &,l(2z[
System.err.println(sMsg); (^NYC$ZxM=
} 9Vru,7g
GXp`yK9c
ZZn$N-
public static void log(int sMsg) 4_`(c1oA
{ a$j ~YUG_
System.err.println(sMsg); 16ZyLt
} dEZUK vo
} p0[+Zm{#l
.P <3+
: eCeJ~&E
/* E<jW;trt_
**TestMethod.java N;`/>R4|I
*/ en'"" w
package NetFox; mqj-/DN6*
c: r25
j4<K0-?
public class TestMethod { kO5lLqE
2t4\L3
PY;tu#W!%
public TestMethod() ua)jGif
{ ///xx/weblogic60b2_win.exe $AT@r"
try{ oOLey!uZw
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); vK%*5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); o@BV&|
SiteFileFetch fileFetch = new SiteFileFetch(bean); .faf!3d
fileFetch.start(); *s,[Uy![
} Cs_&BSs
catch(Exception e){e.printStackTrace ();} *E*oWb]H
XC5/$3'M&
4-t^?T:qF
} -OSj<m<
D#G%WT/"
2j:0!%
public static void main(String[] args) m`l9d4p w?
{ ^$50[
new TestMethod(); <|3%}?
} +U1 Ir5Lx
} Z2gWa~dBC
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