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)); K10G+'H^
} i,6OMB $
for(int i=0;i<nEndPos.length-1;i++) -DI >O/
{ ?doI6N0T
nEndPos = nStartPos[i+1]; #T=iS(i
} vpQ&vJfR
nEndPos[nEndPos.length-1] = nFileLength; {L-^J`> G
} )DgXsT
} y )QLR<wf
GG%b"d-
6G8No-#y
//启动子线程 ^O07GYF
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; }Fe6L;^;
for(int i=0;i<nStartPos.length;i++) eZ'8JU]
{ RkYdK$|K
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CMj =4e
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), OX_y"]utU
nStartPos,nEndPos,i); aI=p_+.h
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3&hR#;,"X
fileSplitterFetch.start(); sscbf
} )|~K&qn`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6}"%>9
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *u},(4Qf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", KF%BX~80C
nEndPos = " + nFileLength); JipNI8\r
// fileSplitterFetch[nPos.length-1].start(); AyE*1 FD
.9J^\%JD
I9X\@lTf
//等待子线程结束 H$`U] =s|
//int count = 0; ]LvP)0=
//是否结束while循环 m{IlRf'
boolean breakWhile = false; v;,W ^#`
4.O)/0sU
)OI}IWDl
while(!bStop) )D8op;Fn
{ K9N31'
write_nPos(); lC5zqyG
Utility.sleep(500); CFpBosoFt^
breakWhile = true; ufXWK3~\
'2lV(>"
/YJo"\7
for(int i=0;i<nStartPos.length;i++) -.D?Z8e
{ L3eF BF/
if(!fileSplitterFetch.bDownOver) d{fd5jv;
{ RY;V@\pRY+
breakWhile = false; pwo$qs(p
break; rJiF2W
} ]it. R-
} Gu$/rb?
if(breakWhile) c=v016r\
break; m` 1dB%;?
o/-RGLzAo
-Q? i16pM
//count++; ^Mq/Cf_T
//if(count>4) A@?0(
// siteStop(); ag'hHFV
} +$C9@CZM9
ct\msG }b:
aE0R{yupZ
System.err.println("文件下载结束！"); .$\-{)
} S)hDsf.I
catch(Exception e){e.printStackTrace ();} -r*|N.5c
} It3k#A0
jf)cDj2
Do4hg $:40
//获得文件长度 P%R!\i
public long getFileSize() 'xS@cFo(
{ 2/3yW.C
int nFileLength = -1; 7rD 8
try{ '{WEyhaS
URL url = new URL(siteInfoBean.getSSiteURL()); t?9J'.p
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b36{vcs~
httpConnection.setRequestProperty("User-Agent","NetFox"); X3sAy(q
)M;~j
y A5h^I
int responseCode=httpConnection.getResponseCode(); 0[UI'2
if(responseCode>=400) DOyO`TJi
{ k (AE%eA
processErrorCode(responseCode); J* !_O#
return -2; //-2 represent access is error FWu:5fBZY
} e (]]
g#(+:^3'
q:kGJxfaW
String sHeader; 5QqU.9M
8s22VL
Xc[ym
for(int i=1;;i++) e(wc [bv
{ =x+1A)Q
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); }@LIb<Y
//Utility.log(in.readLine()); z#G\D5yX[*
sHeader=httpConnection.getHeaderFieldKey(i); rhLhFN{h
if(sHeader!=null) L{~ ]lUo
{ ?5't1219
if(sHeader.equals("Content-Length")) TeuZVy8a
{ i'<hT q4
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); XR",.3LD
break; bbq`gEV
} 4U\>TFO
} ^+-QY\N j
else { 1~]}K2
break; SN)Czi#7
} ^/Hf$tYI!`
} l\0PwD
catch(IOException e){e.printStackTrace ();} n3?P8m$
catch(Exception e){e.printStackTrace ();} P'iX?+*
Q.9,W=<6
^5MM<73
Utility.log(nFileLength); KT<i%)t2
Fep@VkN
Zz (qc5o,F
return nFileLength; gna!Q
} *0oa2fz%
!^Ay!
De3;}]wC
//保存下载信息（文件指针位置） B (eXWWT_
private void write_nPos() wx-&(f
{ -hfDf{QN
try{ 7h(
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8~qpOQX^V
output.writeInt(nStartPos.length); t{UWb~"
for(int i=0;i<nStartPos.length;i++) ;~ Xjk
{ }JOz,SQHP
// output.writeLong(nPos); E_30)"]
output.writeLong(fileSplitterFetch.nStartPos); D]d! lMK/
output.writeLong(fileSplitterFetch.nEndPos); sAO/yG
} o9ys$vXt*
output.close(); K~]Xx~F
} )s7EhIP
catch(IOException e){e.printStackTrace ();} !<h9XccN
catch(Exception e){e.printStackTrace ();} wmK;0 )|H
} o;9H~E
rv)Eg53Q
P5dD&
//读取保存的下载信息（文件指针位置） h`Ej>O7m
private void read_nPos() 7^)yo#i4
{ ?N+pWdi
try{ 8>|4iT
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4`5W] J]6
int nCount = input.readInt(); J#w=Z>oz<
nStartPos = new long[nCount]; \4G9fR4
nEndPos = new long[nCount]; 7!o#pt7
for(int i=0;i<nStartPos.length;i++) ?TDmW8G}J
{ oN83`Z
nStartPos = input.readLong(); Tz:,l$
nEndPos = input.readLong(); @VND}{j
} a~VW?wq
input.close(); b*Hk} !qH
} '&|%^9O/"
catch(IOException e){e.printStackTrace ();} \(?d2$0m
catch(Exception e){e.printStackTrace ();} %"E!E1_Sv
} #~rQ\A!4
<|3F('Q"
K^/.v<w
private void processErrorCode(int nErrorCode) D!)h92CIDm
{ } ?+0s=Z
System.err.println("Error Code : " + nErrorCode); e'v_eD T^
} Mu" vj*F
iF:NDqc
Q&&=:97d
//停止文件下载 :E|+[}|
public void siteStop() ]]u_Mdk
{ )DW".c
bStop = true; O"[#g
for(int i=0;i<nStartPos.length;i++) VzM (u_)
fileSplitterFetch.splitterStop(); K(NP%:
tuo'Uk)
aO:A pOAO
} N>j*{]OY+{
} JV;VR9-l
//负责部分文件的抓取 !cO<N~0*5x
**FileSplitterFetch.java F9IPA%
*/ ?a?] LIE8
package NetFox; zs-,Y@ZL
ccW{88II7w
7pH[_]1"
import java.io.*; P6'0:M@5
import java.net.*; *:chN' <
@nj`T{*.
(/P-9<"U
public class FileSplitterFetch extends Thread { %CrpUx
(WGEX(|
X=k|SayE8
String sURL; //File URL *; 6LX
long nStartPos; //File Snippet Start Position rN~V^k
long nEndPos; //File Snippet End Position taSYR$VJ
int nThreadID; //Thread's ID !6+V
boolean bDownOver = false; //Downing is over FxXnX
boolean bStop = false; //Stop identical cPl$N5/5
FileAccessI fileAccessI = null; //File Access interface (bogAi3<F
;p(Doy)i
0te[i*G
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException z)FGbX
{ P9#}aw+
this.sURL = sURL; ( 2KopL
this.nStartPos = nStart; ;uU 8$
this.nEndPos = nEnd; #fF';Y7
nThreadID = id; h`:gMhn
fileAccessI = new FileAccessI(sName,nStartPos);//定位 qEPC]es|T
} o l+*Oe
)9rJ]D^B
s9?H#^Y5u
public void run() 5lm>~J!/^
{ VSm{]Z!x
while(nStartPos < nEndPos && !bStop) rge/qUr/^
{ &m@DK>
Z uO 7N
Czd)AVK
try{ TC._kAm
URL url = new URL(sURL); ?w"zW6U
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5SHZRF(. 2
httpConnection.setRequestProperty("User-Agent","NetFox"); WS ^%< h#
String sProperty = "bytes="+nStartPos+"-"; zO)3MC7l*
httpConnection.setRequestProperty("RANGE",sProperty); )m(?U
Utility.log(sProperty); H*EN199
\w@ "`!%
DqBiBH[%h
InputStream input = httpConnection.getInputStream(); #;>v,Jo
//logResponseHead(httpConnection); [`|gj
ksli-Px
;[[oZ
byte[] b = new byte[1024]; -Y/c]g
int nRead; 1ihdH1rg[
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -|&&lxrwh
{ MJI`1*(
nStartPos += fileAccessI.write(b,0,nRead); rIWQD%Afm
//if(nThreadID == 1) xEqr3(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 6^"Spf]
} *TP>)o
qv$m5CJvK
>du|DZq
Utility.log("Thread " + nThreadID + " is over!"); a}/A]mu
bDownOver = true; tx||<8
//nPos = fileAccessI.write (b,0,nRead); #\$AB_[ot>
} o) ,1R:
catch(Exception e){e.printStackTrace ();} WBY_%RTx
} % (x9~"
} 4,qhWe`/
#hF(`oX}4K
tsN,yI]-VA
//打印回应的头信息 X_2pC|C
public void logResponseHead(HttpURLConnection con) pt=H?{06
{ bGe@yXId5
for(int i=1;;i++) ,\=,,1_
{ SK;c D>)
String header=con.getHeaderFieldKey(i); Ud'/ 9:P
if(header!=null) BXB ZX@jVk
//responseHeaders.put(header,httpConnection.getHeaderField(header)); I7e.pm
Utility.log(header+" : "+con.getHeaderField(header)); bOS; 1~~
else :pvJpu$]
break; :SvgXMY@
} M#;"7Qg
} h0)Dj(C
'CA{>\F$F+
fm1yZX?`
public void splitterStop() H[D<G9:
{ yU'<b.]
bStop = true; XsbYWJdds
} 9vI<\ Xa
jcL%_of
xY>@GSO1
} L(+I
z~(3S8$
u.dYDi
/* xTg=oq
**FileAccess.java P+bA>lJd
*//文件访问(定位，写) K$/&C:,Q
package NetFox; k{ ~0BK
import java.io.*; _=-B%m
cK.z&y0]
7]H<ou
public class FileAccessI implements Serializable{ ,8G6q_ud
uN8RG_Mb
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 XR|U6bf]
RandomAccessFile oSavedFile; )9i$ 1"a(
long nPos; @|([b r|O
YJu~iQ`i
j9xu21'!%
public FileAccessI() throws IOException v6P2v
{ 0TWd.+
this("",0); QTC!vKM
} oju,2kpH7#
QtQbr*q@%
"fu:hHq
public FileAccessI(String sName,long nPos) throws IOException .F},Z[a&
{ O',Vce$
oSavedFile = new RandomAccessFile(sName,"rw"); N@0cn q:"
this.nPos = nPos; ;2P
oSavedFile.seek(nPos); }Xvm( ;
} "S H=|5+
Qk72ra)
Bmt^*;WY+
public synchronized int write(byte[] b,int nStart,int nLen) QQJf;p7
{ s }Ql9
int n = -1; rCUGaf~
try{ 5]xSK'6W
oSavedFile.write(b,nStart,nLen); F1meftK
n = nLen; "+E\os72|
} YPW UncV
catch(IOException e) 0X3yfrim
{ Wdi`ZE
e.printStackTrace (); McpQ7\*h
} ,Qs%bq{t
``%yVVg}
Gk]ZP31u
return n; ,u>[cRqw
} IC?(F]$%>
#_{Q&QUk
6$[7hlE
} bQ(-M:
0` .5gxm
R0%M9;>1
/* 0<O()NMv
**SiteInfoBean.java Q8MIpa!:
*/ hD=.rDvO
package NetFox; <{GVA0nr
]f0OmUHR5i
]IEZ?+F,
public class SiteInfoBean { Ptf(p`
#*:^\z_Jd
N<1+aL\
private String sSiteURL; //Site's URL ,yA[XAz~U
private String sFilePath; //Saved File's Path k/D{&(F ~
private String sFileName; //Saved File's Name U(#JC(E-#
private int nSplitter; //Count of Splited Downloading File 1X&.po
g/fpXO\
7[w<v(Rc
public SiteInfoBean() ypyKRsx
{//nSplitter的缺省值为5 B0%=!&
//default value of nSplitter is 5 xP!QV~$>
this("","","",5); bMxK@$G~
} ;0Pv49q
|?ssHW
tM^4K r~o,
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) n{i,`oQ"
{ ,T`,OZm
sSiteURL= sURL; Id##367R
sFilePath = sPath; 4A6Yl6\Y
sFileName = sName; {eV8h}KIl
this.nSplitter = nSpiltter; [IQ|c?DxpL
ZGDT 6,
".tL+A[
} 2Jio_Hk
YT Zi[/
i*Ldec^
public String getSSiteURL() hg(<>_~
{ Iz5NA0[=2
return sSiteURL; qfyZda0d
} p.SipQ.P
6FQi=}O1
R2gV(L(!!
public void setSSiteURL(String value) Z(T{K\)uN
{ 1(Ta*"(0Ip
sSiteURL = value; 7l=;I%
} N);w~)MYh
67YC;J]n=z
w8UuwFG?<
public String getSFilePath() IB/3=4n^|
{ );\c{QF
return sFilePath; >F7w]XH
} La;GS
_XV%}Xb'
S3E,0%yo+)
public void setSFilePath(String value) e "A"
{ iqQT ^
sFilePath = value; L^3&
} 8Ojqm#/f
P5h|* ?=
] 3"t]U'f
public String getSFileName() ?)xIn)#ls
{ U]iI8c
return sFileName; h'):/}JPl
} GQqGrUQ*}
[y[d7V9_o
CJBf5I3
public void setSFileName(String value) mll:rWC)
{ O?JJE8~']
sFileName = value; =_7wd*,
} QPJ\Iu@D$
*1b|j|5v
`p\=NP!n
public int getNSplitter() dAh.I3
{ Ke\\B o,
return nSplitter; ?Z7`TnG$uf
} z)qYW6o%
lLx!_h
>='/%Ad
public void setNSplitter(int nCount) `@~e<s`j
{ .f\LzZ-I:
nSplitter = nCount; \G" S7
} wA"@t
} #DTKz]i?
t'eqk#rq
_ E;T"SC
/* 9y7N}T6
**Utility.java `8:)? 0Ez
*/ Z2%HQL2
package NetFox; =3e7n2N)
,XD" p1(|G
PsY![CPrW
public class Utility { uN|A}/hr]
Da=EAG-{7
[GLH8R
public Utility() ?[D3-4
{ @I_cwUO
rhJ&* 0M
{Su?*M2y
} ]?eZDf~
_C?j\Wy
//线程睡眠 QQ*sjK.(
public static void sleep(int nSecond) oaY_6
{ Yh":>~k?SY
try{ [2%[~&4
Thread.sleep(nSecond); t un}rdb
} dGIdSQ~ _
catch(Exception e) +#}GmUwPG$
{ 9mF'
e.printStackTrace (); N'Gq9A
} R=D]:u<P
} 2w?q7N%
vCzZjGBY
//日志 8Sbz)X
public static void log(String sMsg) mzgt>Qtkz=
{ pGbfdX
System.err.println(sMsg); vB:\ZX4
} ,+=9Rp`md
!FEc:qH
X\}l" ]
public static void log(int sMsg) i2F7O"f.
{ <I+kB^Er
System.err.println(sMsg); iHa?b2=)
} 9:j?Jvw$
} +C(-f
5ut| eD`3
W5*ldXXk
/* sS D8Sx/
**TestMethod.java > I2rj2M#
*/ Z}W{ iD{
package NetFox; 5NU{y+
&Mh.PzO=b
' \JE>#
public class TestMethod { b!<_ JOL2.
#M,&g{
+8Xjk\Hi
public TestMethod() z7K{ ,y
{ ///xx/weblogic60b2_win.exe Hon2;-:]{]
try{ 8 Rx@_
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); *PJH&g#Ge
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); A*JOp8\)
SiteFileFetch fileFetch = new SiteFileFetch(bean); B8&q$QV
fileFetch.start(); mdi!Q1pS
} i:lc]B
catch(Exception e){e.printStackTrace ();} s~M4.06P
?N#I2jxaD
p`tz*ewC
} I _nQTWcm
uEPp%&D.+
v{u3[c
public static void main(String[] args) MxTJgY
{ "?" :
new TestMethod(); }:m#}s
} Mz@{_*2
} T:^.; ZY
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