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)); foi@z9
} "PI]k
for(int i=0;i<nEndPos.length-1;i++) 6[{|'
{ q!sazVaDp
nEndPos = nStartPos[i+1]; Fhr5)Z
} SCUsDr+.
nEndPos[nEndPos.length-1] = nFileLength; :hA=(iz
} |hlc#t?
} <691pkX
6n
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//启动子线程 ohod)8
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; h\@\*Xz<v
for(int i=0;i<nStartPos.length;i++) /%P|<[< [
{ x_yQoae
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $^ wqoW%t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), {okx*]PIc
nStartPos,nEndPos,i); qVpV ZH!
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); , '_y@9?I
fileSplitterFetch.start(); Xc!0'P0T
} R}S@u@mOE
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), MzWVsV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); lebwGW,!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?df*Y5I2
nEndPos = " + nFileLength); @'Y^A
// fileSplitterFetch[nPos.length-1].start(); X5V8w4NN
X:ck
eMDO;q
//等待子线程结束 <x^Ab#K"
//int count = 0; , Ac gsC
//是否结束while循环 )nI}KQJ<
boolean breakWhile = false; Qel2OI`b
+5>*$L%8T`
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while(!bStop) WLB@]JvTBY
{ :7&-<ae2
write_nPos(); f7mN,_Lt
Utility.sleep(500); V2&O]bR
breakWhile = true; zK5/0zMZ
ZYi."^l
+;ILj<!Z7
for(int i=0;i<nStartPos.length;i++) C1V@\mRi
{ _(R1En1
if(!fileSplitterFetch.bDownOver) p#yq'kY
{ L93PDp4v
breakWhile = false; "Q>gQKgL
break; ]rpU3 3
} }#0i1]n$D
} \m\E*c ):
if(breakWhile) PqhR^re0.
break; 6hW ~Q
WaaF;|,(
2EU((Q`>=(
//count++; 3)bC,
//if(count>4) [i&EUvo
// siteStop(); lHTW e'
} Pa8E.<>
8`0/?MZ)
rQuozbBb
System.err.println("文件下载结束！"); ./iC
} \fk%^1XY
catch(Exception e){e.printStackTrace ();} 91Fx0(
} ;E!(W=]*F
Rfk8trD B
_yu d
//获得文件长度 =tS1|_
public long getFileSize() \E!a=cL!
{ #jc+2F,+{
int nFileLength = -1; qt.G_fOz
try{ ]WO0v`xh
URL url = new URL(siteInfoBean.getSSiteURL()); ,bLHkBK
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S-4C>gM
httpConnection.setRequestProperty("User-Agent","NetFox"); s.zfiJ
nz?jNdyz
x3`b5^
int responseCode=httpConnection.getResponseCode(); whA
if(responseCode>=400) +bGj(T%+'
{ *i=+["A
processErrorCode(responseCode); vZ rE9C }
return -2; //-2 represent access is error h8ikM&fl
} Ci}v+
+i@r-OL
74h[YyVi
String sHeader; P_[A
-Tzp;o
m,u5S=3A{!
for(int i=1;;i++) S m%\,/3
{ t=K;/1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }^}fx [
//Utility.log(in.readLine()); m$bX;F}T
sHeader=httpConnection.getHeaderFieldKey(i); v}Gpw6
if(sHeader!=null) sM4Qu./
{ {1<XOp#b
if(sHeader.equals("Content-Length")) #lf3$Tm D
{ w6PKr^
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &7}\mnhB
break; G<5i %@
} x=/`W^t2
} l\?HeVk^
else e13{G@
break; Zgw;AY.R>
} ':mw(`
} T~238C{vh
catch(IOException e){e.printStackTrace ();} AB.gVw| 4
catch(Exception e){e.printStackTrace ();} /z0X
L,m'/}$
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Utility.log(nFileLength); tfSY(cXg'T
NB["U"1[^E
M<AjtDF%
return nFileLength; ;T9u$4<
} tR!!Q
|<Cz#| ,q
3k#?E]'
//保存下载信息（文件指针位置） <;O-N=
private void write_nPos() 9i&(VzY[=
{ 6 aE:vR2
try{ udEJo~u
output = new DataOutputStream(new FileOutputStream(tmpFile)); j[^(<R8
output.writeInt(nStartPos.length); a-A>A_.
for(int i=0;i<nStartPos.length;i++) ']bpsn
{ !zu YO3:
// output.writeLong(nPos); s!vvAD;\
output.writeLong(fileSplitterFetch.nStartPos); \NiW(!Z}
output.writeLong(fileSplitterFetch.nEndPos); ?^8CD.|
} Ve]ufn6
output.close(); e(5:XHe
} .tg2HKD_lW
catch(IOException e){e.printStackTrace ();} .IO_&^
catch(Exception e){e.printStackTrace ();} k2"DFXsv
} c]eDTbXd
{.D^2mj|
zq:+e5YT?T
//读取保存的下载信息（文件指针位置） n]15 ~GO.
private void read_nPos() n!Ic.T3PA
{ Xscm>.di
try{ WDM^rjA|j
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); g!#M0
int nCount = input.readInt(); 4*)a3jI?
nStartPos = new long[nCount]; MRI`h.
nEndPos = new long[nCount]; s_/a1o
for(int i=0;i<nStartPos.length;i++) ]uikE2nn
{ jHU5>Gt-}
nStartPos = input.readLong(); bv NXA*0
nEndPos = input.readLong(); V!|:rwG2
} k\ 2.\Lwb
input.close(); n^a&@?(+
} ;fdROI
catch(IOException e){e.printStackTrace ();} !LG 5q/}&
catch(Exception e){e.printStackTrace ();} 6>fQe8Y
} IbC8DDTD
d*Wg>8|
&D/@H1fBe
private void processErrorCode(int nErrorCode) 3ih3O
{ ]12ypcf
System.err.println("Error Code : " + nErrorCode); DE$HF*WY
} Pl>BTo>p'
aX)k(*|
LNA5!E
//停止文件下载 _3pME9l
public void siteStop() l{2Y[&%
{ RF#S=X6
bStop = true; T[?toqkD>z
for(int i=0;i<nStartPos.length;i++) P2j"L#%
fileSplitterFetch.splitterStop(); 8Hdm(>
AjW5H*
y<h~jz#hkq
} -MCDX^>P
} dr54D
//负责部分文件的抓取 K[.*8
**FileSplitterFetch.java o>#ue<Bc6
*/ Fm|h3.`V
package NetFox; q JdC5z\[
VJ8"Q
]1^F
import java.io.*; _#SCjFz
import java.net.*; M<%g)jn_
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k|r+/gIV
public class FileSplitterFetch extends Thread { -;i vBR
0bcbH9) 1q
LdPA`oI3j
String sURL; //File URL 5Nt40)E}sN
long nStartPos; //File Snippet Start Position BDO]-y
long nEndPos; //File Snippet End Position \qo}}I>e
int nThreadID; //Thread's ID RqONVytx
boolean bDownOver = false; //Downing is over iB1+4wa
boolean bStop = false; //Stop identical "u H VX|`
FileAccessI fileAccessI = null; //File Access interface :/.SrkN(A7
~8j4IO(
.#4;em%7
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException =B/Ac0Y
{ )R- e^Cb
this.sURL = sURL; kdam]L:9
this.nStartPos = nStart; L]syDn
this.nEndPos = nEnd; cD6T4
nThreadID = id; S,*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 TTfU(w%&P
} Yu`KHvur
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o)M=; !
public void run() 3jJd)C R
{ ` 465 H
while(nStartPos < nEndPos && !bStop) 2JMMNpya
{ -Y{=bZS u
pSPVY2qKX
hd'JXKMy
try{ Za>0&Fnf
URL url = new URL(sURL); T\ cJn>kCn
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -!ARVf *
httpConnection.setRequestProperty("User-Agent","NetFox"); v)!C Dpw
String sProperty = "bytes="+nStartPos+"-"; ^&Re-{ES]
httpConnection.setRequestProperty("RANGE",sProperty); Wifr%&t{J
Utility.log(sProperty); 2H]~X9,z2
HTa]T'
PdkS3Hz
InputStream input = httpConnection.getInputStream(); iVQ)hsW/
//logResponseHead(httpConnection); 0o>l+c
G|LJOq7QB
hk7kg/"
byte[] b = new byte[1024]; pAm L
int nRead; E[nJ'h<h
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) j@98UZ{g\
{ mZgYR~
nStartPos += fileAccessI.write(b,0,nRead); bo]= *
//if(nThreadID == 1) "A>/m"c]*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); m0a<~
} Or2J
Ibbpy++d[
Z7Gl^4zn
Utility.log("Thread " + nThreadID + " is over!"); d$;1%rRj8
bDownOver = true; v<Ozr:lL
//nPos = fileAccessI.write (b,0,nRead); |#Q4e51H
} #% 1|$V*:
catch(Exception e){e.printStackTrace ();} /ll2lyS+
} o=}vK[0u
} yf/c
Bm\OH#
sT;:V
//打印回应的头信息 !ot$Q
public void logResponseHead(HttpURLConnection con) ?%]?#4bkc
{ mD]^a;U[X
for(int i=1;;i++) Cbq|<p# #o
{ Z4ZR]eD
String header=con.getHeaderFieldKey(i); #n5DK{e
if(header!=null) -IP3I
//responseHeaders.put(header,httpConnection.getHeaderField(header)); o(|fapK.
Utility.log(header+" : "+con.getHeaderField(header)); w<o#/J9
else _]/&NSk
break; M6MtE_E
} f:K3 P[|
} IW&.JNcN
"x"y3v'
h{BO\^6x
public void splitterStop() _ITA$#
{ _XP3|E;I/
bStop = true; pRTdP/(OQ
} .o"FT~}z
b- FJMY
wvuh
} B+pJWl8u
Kd%>:E*
l4LowV7
/* U*R
**FileAccess.java }w%W A&"W
*//文件访问(定位，写) sP` k{xG
package NetFox; ->0OqVQA
import java.io.*; Ozo)}
B*,Qw_3dG
sO;]l"{<
public class FileAccessI implements Serializable{ }8\"oA6
=JK# "'
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8ba*:sb
RandomAccessFile oSavedFile; 6Y-sc*5
long nPos; SaA9)s
LqOjVQxz
rjJ-ZRs\
public FileAccessI() throws IOException v."0igMO
{ P?Fm<s:
this("",0); s(3iGuT
} {W5D)
l*0`{R
YYiT,Xp<A
public FileAccessI(String sName,long nPos) throws IOException P:3%#d~q
{ [ ]LiL;A&
oSavedFile = new RandomAccessFile(sName,"rw"); :87HXz6]jS
this.nPos = nPos; ,2y" \_
oSavedFile.seek(nPos); UB7H`)C}
} I$#)k^Q
UN"U#Si)
IY=CTFQ8lm
public synchronized int write(byte[] b,int nStart,int nLen) ~l@-gAyw
{ @U;U0
int n = -1; ~?x `f+
try{ RE?j)$y?`
oSavedFile.write(b,nStart,nLen); 4t<l9Ilp
n = nLen; G"'[dL)N>
} HsQ\xQ"k!
catch(IOException e) d mj T$a|
{ ?xgrr7
e.printStackTrace (); N`Q[OFe
} 0 3/<A^
iO?Sf8yJ:
*?Pbk+}%
return n; TM1D|H
} $!-a)U,w$B
ktMUTL(B
4qc0QA%
} 3"pl="[*
w' gKE'c
~l=Jx*
/* |##rs
**SiteInfoBean.java _?IP}}jA:
*/ ?7:?OX
package NetFox; 8pQ:B/3=
i H^Gv*
HR> X@g<c
public class SiteInfoBean { ^^{gn3xJ
,svj(HP$
ZGHh!Ds;
private String sSiteURL; //Site's URL RlH~<|XK
private String sFilePath; //Saved File's Path XJ.ERLR.
private String sFileName; //Saved File's Name .bT|:Q~@{
private int nSplitter; //Count of Splited Downloading File \XUG-\$p
~_YU%y
YhzDi>hob
public SiteInfoBean() w=txSF&Qr
{//nSplitter的缺省值为5 '/@]V
//default value of nSplitter is 5 t;~H6
this("","","",5); =rrbS8To=
} fcC?1M[BP~
>[U.P)7;
*k7vm%#ns
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) NIQX?|;b{
{ D#~S<>u@
sSiteURL= sURL; <g^!xX<r?
sFilePath = sPath; Owa]ax5
sFileName = sName; 3?"JFfYU,'
this.nSplitter = nSpiltter; NP {O
\~YyY'J
@fVCGV?'
} {m&8Viq1
ezOZHY>|#
w?+v+k\
public String getSSiteURL() 96&Y
{ i7m=V T
return sSiteURL; R4RSXV
} VgSk\:t
#1v>3H(
N]k(8K
public void setSSiteURL(String value) 8#S}.|"?F
{ jC)lWD
sSiteURL = value; xTJ-v/t3<
} kr_!AW<.tz
njk1x
y.LJ5K$&a
public String getSFilePath() xGzp}
{ ;8G( l
return sFilePath; LD~s@}yH>
} #0+`dI_5/
PUdJ>U
NB z3j
public void setSFilePath(String value) P0En&g+~
{ Zy -&g:
sFilePath = value; ZL-YoMHc+_
} '|\et aD
R`RLq1WA
&y}nd 7o
public String getSFileName() g8_C|lVZi
{ E[FRx1^R9
return sFileName; f.o,VVYi
} as{^~8B
1xJc[q
\I"UW1)B
public void setSFileName(String value) 5nGDt~a
{ ]vPa A
sFileName = value; Au6*hv3:
} 4[S0~O{r
WG{mg/\2(C
]J t8]w
public int getNSplitter() 4<['%7U_[
{ yvgn}F{}
return nSplitter; jQKlJi2xu
} \xH#X=J
"\'g2|A
^Fl6-|^~
public void setNSplitter(int nCount) \qrSJ=}t
{ 1D0_k
nSplitter = nCount; +b7}R7:AFH
} 8"M*,?.]
} K$H>/*&'~
,=9e]pQ
Dm=Em-ST6
/* G n_AXN
**Utility.java da[u@eNrnX
*/ uh~/ybR
package NetFox; q>~\w1%}a\
}@*Me+
GnE%C2L-
public class Utility { `>1"v9eF
idC4yH42
)TceNH
public Utility() .oJs"=h:m
{ cm8-L[>E
7-oH >OF^
rpgr5>
} 5dVSir
?/_8zpW
//线程睡眠 0,T'z,
public static void sleep(int nSecond) |EJ&s393&
{ ?Jlz{msI
try{ 3&D;V;ON}_
Thread.sleep(nSecond); &=sVq^d@qe
} s<I[)FQVr
catch(Exception e) XIu3n9g^#
{ TU&t 1_6
e.printStackTrace (); l_lm)'ag
} sOJH$G3O
} zFjG20w%3g
w$9aTL7
//日志 ) 0x*>;"o
public static void log(String sMsg) No)v&P%
{ Tr1#=&N0
System.err.println(sMsg); 9})!~r;|
} zfE;)K^"
aW8Bx\q
`L(AvSR
public static void log(int sMsg) y)W.xR
{ Ge+&C RhyX
System.err.println(sMsg); ZDZPJp,
} lD!o4ZAo
} ()}B]?
1n! JfsU
APT'2-I_
/* AW8"@
**TestMethod.java P!C!E/Jf5
*/ ny5= =C{9
package NetFox; |H.(?!nTb
8k$iz@e
,Ty>sZ#/fz
public class TestMethod { )*@Oz
D<[4}og&]
*M_.>".P
public TestMethod() P-L<D!25
{ ///xx/weblogic60b2_win.exe >Au]S`
try{ IKM=Q. 7j
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4-`C !q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =|n NC
SiteFileFetch fileFetch = new SiteFileFetch(bean); DT #1*&-
fileFetch.start(); Dg]ua5jk
} W"fdK_F\
catch(Exception e){e.printStackTrace ();} )-824?Nl:
W:uIG-y~
J!,5HJh1
} ]6{G;f$
29g("(}TK
(=${@=!z
public static void main(String[] args) Sd.i1w&
{ WigC'
new TestMethod(); >JFAE5tj&2
} ^f{+p*i}:
} tvptawA.
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