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)); .f[\G*
} h?M'7Lti
for(int i=0;i<nEndPos.length-1;i++) GhaAvyN
{ j>0SE
nEndPos = nStartPos[i+1]; DRS;lJ2
} KHiYV
nEndPos[nEndPos.length-1] = nFileLength; L8%=k%H(1
} ant-\w>}
} D<$j`r
LKoM\g(
K'ed5J
//启动子线程 u^;sx/
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %6vMpB`g
for(int i=0;i<nStartPos.length;i++) EC:x,i
{ sP=2NqU3Q
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), BUboP?#%)
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), KG7X8AaK#
nStartPos,nEndPos,i); 70I4-[/z[d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A_8`YN"Xk
fileSplitterFetch.start(); `RL(N4H
} `-E.n'+
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), _j|n}7a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); GNj/jU<o!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 'ocwXyP,
nEndPos = " + nFileLength); ,L8I7O}A;
// fileSplitterFetch[nPos.length-1].start(); cftn`:(&8
!~VR|n-
mDe+ M{/
//等待子线程结束 Ynt&cdK9
//int count = 0; +$an*k9
//是否结束while循环 5Od(J5`
boolean breakWhile = false; '8((;N|I^
;Ln7_
8*Nt&`@
while(!bStop) gs<qi'B
{ #z1ch,*3;
write_nPos(); jn#N7%{Mk
Utility.sleep(500); G> 5=`
breakWhile = true; z.\[Va$@l
8EVF<@{]
}(hYG"5
for(int i=0;i<nStartPos.length;i++) Jh/M}%@|
{ 9#.NPfMF
if(!fileSplitterFetch.bDownOver) e`gGzyM
{ /ltP@*bo
breakWhile = false; }rb ]d'|
break; 8Y;zs7Y
} %`<`z yf
} Y+Q,4s
if(breakWhile) d5Eee^Qu/
break; `)xU;-
zMHf?HQ-Z
<aQ; "O~
//count++; M<|~MR
//if(count>4) 1\7"I-
// siteStop(); \!4ghev3
} ?yd(er<_f
9_CA5?y$:
4<K ,w{I
System.err.println("文件下载结束！"); LMhY"/hAXa
} j#.-MfB
catch(Exception e){e.printStackTrace ();} Duo#WtC
} SS<+fWXE
v"?PhO/{=
QYCNO#*
//获得文件长度 P*qNRP%
public long getFileSize() BIB>U W
{ o^"d2=
int nFileLength = -1; 7l|>
try{ ~QQ23k&
URL url = new URL(siteInfoBean.getSSiteURL()); 1rzq$,O
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); \t~u :D
httpConnection.setRequestProperty("User-Agent","NetFox"); S0o,)`ZB
\gk3w,B?E
@|*Z0bn'
int responseCode=httpConnection.getResponseCode(); G5eLs
if(responseCode>=400) v!v0,?b*
{ B}xo|:f!zj
processErrorCode(responseCode); {Z{NH:^
return -2; //-2 represent access is error qh'f,#dI}
} H ]N/Y{
m3v*,~
>p+gx,N
String sHeader; 4 d1Y\
F|ML$
S:GUR6g8D
for(int i=1;;i++) do?n /<@o
{ R?e7#HsJ
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cB"F1~z
//Utility.log(in.readLine()); o3[sF
sHeader=httpConnection.getHeaderFieldKey(i); cX]{RVZo-/
if(sHeader!=null) Q)|LiCR,
{ Wg;TXs/
if(sHeader.equals("Content-Length")) $vicHuX!
{ PQI,vr'R
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); +cOI`4`$
break; eVK<%r=
} Q24:G
} (Vv[
else }4ghT(C}$
break; qYrGe
} g!|E!\p
} !JQ~r@j
catch(IOException e){e.printStackTrace ();} ;<GTtt#D
catch(Exception e){e.printStackTrace ();} _"t.1+-K
%TggNU,
}oxaB9r
Utility.log(nFileLength); ";Xbr;N
0FR%<u
).`a-Pv
return nFileLength; RxeRO2
} zinl.8Uk
*9:6t6x
vi.AzO
//保存下载信息（文件指针位置） D]`B;aE>A*
private void write_nPos() O,,n
{ *B~:L"N
try{ v{*X@)$
output = new DataOutputStream(new FileOutputStream(tmpFile)); _G*x:<
output.writeInt(nStartPos.length); 3g "xm
for(int i=0;i<nStartPos.length;i++) - 5Wt9
{ i&G`ah>
// output.writeLong(nPos); EG8R*Cm,}
output.writeLong(fileSplitterFetch.nStartPos); GSb)|mj
output.writeLong(fileSplitterFetch.nEndPos); =FJ9wiL
} >-o:> 5
output.close(); cz~FWk
} !?M_%fNE
catch(IOException e){e.printStackTrace ();} *R6eykp
catch(Exception e){e.printStackTrace ();} X@4d~6k?
} F`}w0=-*(
uU!i`8
={0{X9t?'j
//读取保存的下载信息（文件指针位置） A;nmua-Fv
private void read_nPos() =5_F9nk-
{ P FFw$\j
try{ l6U'
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); TS8E9#1a
int nCount = input.readInt(); (_5+`YsV
nStartPos = new long[nCount]; D&d:>.~u
nEndPos = new long[nCount]; snNg:rTL
for(int i=0;i<nStartPos.length;i++) 4<>:]
{ '>3RZ&O
nStartPos = input.readLong(); zLK ~i>aW
nEndPos = input.readLong(); ~\IDg/9Cj
} aC]l({-0
input.close(); Sqt"G6<
} 3E@&wpj
catch(IOException e){e.printStackTrace ();} 3Qr!?=nf
catch(Exception e){e.printStackTrace ();} &rWJg6/
} EUS]Se2
l"!;Vkg.5
<RsKV$Je I
private void processErrorCode(int nErrorCode) Kd1\D!#!6
{ %,q#f#
System.err.println("Error Code : " + nErrorCode); Cx'=2Y7
} ur[bh
E4ee_`p
fy4JW,c
//停止文件下载 bUB6B
public void siteStop() > V}NG
{ pr89zkYw
bStop = true; '^Np<
for(int i=0;i<nStartPos.length;i++) a~EEow;A
fileSplitterFetch.splitterStop(); VQ3&
o=2`N2AL
({b/J0<@D
} rz7b%WY
} 1T?%i
//负责部分文件的抓取 Wfw9cxGkf
**FileSplitterFetch.java }X:r:{r
*/ phSP+/w
package NetFox; _)" 5 gv
4/vQ=t
bxHk0w
import java.io.*; xT>V;aa\
import java.net.*; 1vd+p!n
7NqV*
tqf-,BLh
public class FileSplitterFetch extends Thread { NVPYv#uK
y>18)8
;BvWU\!
String sURL; //File URL =S +:qk
long nStartPos; //File Snippet Start Position .}>[Kr
long nEndPos; //File Snippet End Position R:<AR.)K
int nThreadID; //Thread's ID M<7*\1
boolean bDownOver = false; //Downing is over lV="IP^7
boolean bStop = false; //Stop identical e]fC!>w(\
FileAccessI fileAccessI = null; //File Access interface 7si.]
[]^>QsS(X
(o=iX,@'2
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Q{kuB+s
{ Y[,C1,
this.sURL = sURL; *~X\c Z
this.nStartPos = nStart; Ms3/P|{"p
this.nEndPos = nEnd; ]F#kM211
nThreadID = id; xB[# a*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 q=(wK&
} fE}}>
@gk[sQ\O
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public void run() 5G[^ah<Tg
{ %"V,V3kw4
while(nStartPos < nEndPos && !bStop) (U<wKk"
{ z05pVe/5
dGN*K}5
@)wXP@7
try{ }c:0cl
URL url = new URL(sURL); 8t; nU;E*
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Jy$-)
httpConnection.setRequestProperty("User-Agent","NetFox"); 5=e@yIr'#
String sProperty = "bytes="+nStartPos+"-"; $]86w8?-N
httpConnection.setRequestProperty("RANGE",sProperty); ?~8V;Qn
Utility.log(sProperty); tO$M[P=b
>MLqOUr#
~Q\[b%>J
InputStream input = httpConnection.getInputStream(); pTd@i1%Nr
//logResponseHead(httpConnection); i ib-\j4d
d4tVK0 ~
$>Do&TU
byte[] b = new byte[1024]; p! 1zhD
int nRead; 2Hj]QN7"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) )VrHP9fu
{ I115Rp0
nStartPos += fileAccessI.write(b,0,nRead); *}=W wG
//if(nThreadID == 1) y6\#{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qr1^i1%\
} BZsxf'eN'
e9nuQ\=
[;+YO)
Utility.log("Thread " + nThreadID + " is over!"); xNU}uW>>T
bDownOver = true; 0jMrL\>C
//nPos = fileAccessI.write (b,0,nRead); Ft7l/
} DoA f,9|_
catch(Exception e){e.printStackTrace ();} aQuENsB
} gUlZcb
} eS M!_2
n$9!G
kQtl&{;k?
//打印回应的头信息 F u)7J4Z
public void logResponseHead(HttpURLConnection con) j\<S6%p#R
{ `!BUd
for(int i=1;;i++) q_)DY f7V}
{ [a2/`ywdV
String header=con.getHeaderFieldKey(i); ?g2K&
if(header!=null) +=v|kd
//responseHeaders.put(header,httpConnection.getHeaderField(header)); QaV*}W
Utility.log(header+" : "+con.getHeaderField(header)); ~V4|DN[I
else [aW#7
break; -!"8j"pA:
} <KCgtO
} e5Z\v0
=W?c1EPLCx
;#*mB`
public void splitterStop() Oi RqqD
{ BL7%MvDQ
bStop = true; ?0F#\0
} 6Z 7$ZQ~
b`' ;`*AN+
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} ) PtaX|U
]d0Dd")n
N|; cG[W
/* riz({
**FileAccess.java IdM;N
*//文件访问(定位，写) \%(R~H
package NetFox; WO^h\#^n
import java.io.*; xxYFWvi
.(krB%N
9;jfg|x1[
public class FileAccessI implements Serializable{ -HOCxR
Z|.z~53;
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ^gy(~u
RandomAccessFile oSavedFile; 3!I8J:GZ:
long nPos; l[gL(p"W
5|Uub,
iw%DQ }$
public FileAccessI() throws IOException yTk9+>
{ 15B$Sp!/`e
this("",0); ZD*>i=S
} g`6S*&8I
Gl+}]Vn[n
Eyuc~[
public FileAccessI(String sName,long nPos) throws IOException ,QDq+93
{ H74hv`G9
oSavedFile = new RandomAccessFile(sName,"rw"); 0x84 Ah)
this.nPos = nPos; 8164SWB
oSavedFile.seek(nPos); /YHeO
} j_Fr3BWS
(%bfNs|
RZ -w,~
public synchronized int write(byte[] b,int nStart,int nLen) 6eb5q/
{ e.Ii@<
int n = -1; 3|C"F-'<
try{ IMBqy-q
oSavedFile.write(b,nStart,nLen); RGcT
n = nLen; Qx:+n`$/
} XHW{EVcF
catch(IOException e) z-,'W`
{ 'Mg%G(3
e.printStackTrace (); l{k
} 'lWNU
nV'B!q
i^=an?}/
return n; f,$FrI,
} H_x35|"
bF3j*bpO"
uzsR*x%s-
} s;A]GJ
YO=;)RA
SU*P@?:/}
/* nC z[#t
**SiteInfoBean.java ]M_)f
*/ Vi]D](^!
package NetFox; RD~QNj9,T
z*FlZLHY
]O 2_&cs
public class SiteInfoBean { T_r[#j
*rWE.4=&
0KEytm]
private String sSiteURL; //Site's URL q.#aeqKBP
private String sFilePath; //Saved File's Path Od"-w<'
private String sFileName; //Saved File's Name #GTmC|[
private int nSplitter; //Count of Splited Downloading File L&eO?I=,
n^'{{@&(v
NKd):>d%
public SiteInfoBean() v5&WW?IBQ
{//nSplitter的缺省值为5 eudPp"Km
//default value of nSplitter is 5 \HRQSfGt
this("","","",5); n32?GRp
} H~ (I
"<=^Sm
A:N!H_x
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fY>\VY$>
{ !\p-|51
sSiteURL= sURL; Um%E/0j
sFilePath = sPath; rGoB&% pc
sFileName = sName; L/V3sSt
this.nSplitter = nSpiltter; EQg 6*V
o#;w>-
1W5YS +pf
} cZ5[A T
2t_E\W7w+
MEg|AhP
public String getSSiteURL() \2W( >_z
{ kQ|}"Tw7
return sSiteURL; |s|RJA1
} X~lOFH;}q
cLamqZf3
MECR0S9
public void setSSiteURL(String value) 7 0KZXgBy_
{ rsrv1A=t?
sSiteURL = value; .3$iOMCH
} N#|c2n+
/bg8oB4
$U!w#|&
public String getSFilePath() x`a@h\n
{ <OpiD%Ctx
return sFilePath; u K 8r
} .2OP>:9F
x!S8'
10*U2FY)]
public void setSFilePath(String value) Rnj2Q!C2
{ 6Bs_" P[
sFilePath = value; GMksr%0Pj
} S# SA:>8s
N+h|Ffnp
6?2/b`k
public String getSFileName() UGl}=hwKkG
{ E|#'u^`yv
return sFileName; 'tF<7\!
} K&Zdk (l)
mh|M O(
H,] D}r
public void setSFileName(String value) ;b(/PH!O
{ B,}%1+*
sFileName = value; {?,:M
} 9'O<d/xj/
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AlGD .K
public int getNSplitter() ,v(G2`Z
{ owQLAV
return nSplitter; 2Ask]
} -0lpsF
IgZX,4i=o
.] 5&\
public void setNSplitter(int nCount) ))u$j4V
{ L[rJ7:
nSplitter = nCount; 8&H1w9NrX_
} %J3#4gG^v
} wMei`svY
9v0f4Pbxm
RDk{;VED{
/* wXfy,W
**Utility.java fH}`
*/ /9W-;l{=z
package NetFox; 3KP6M=
Oxy.V+R
v='7.A
public class Utility { QZ%_hvY[%>
[JsQ/|=z
IB(5 &u.
public Utility() NcRY Ch
{ ,c}Q;eYc3
no^I![_M
^P(HX
} $:F]O$A
d(42ob.Tr
//线程睡眠 %q(n'^#Z.y
public static void sleep(int nSecond) z&9vKF
{ dorZ O2Uc
try{ cD]{ Nn
Thread.sleep(nSecond); WRL &tz
} 5H`k$[3V
catch(Exception e) *_3+ DF
{ WZ;f3 "
e.printStackTrace (); Jc:*X4-'
} .Mdxbs6.C
} D@FJVF7c
-i7W|X"
//日志 4:5CnK
public static void log(String sMsg) 315Rk!{AJ
{ !2$O^ }6"
System.err.println(sMsg); 67')nEQ9
} sR ~1J4
=AGsW
K%$%9y
public static void log(int sMsg) xsV(xk4
{ $yHlkd`Y
System.err.println(sMsg); s0qA8`Yu
} 2y v'DS
} kMf]~EZ?
)nTOIfP2
mvlK~c8
/* n"-cX)
**TestMethod.java J*A<F'^F1
*/ )!e-5O49r
package NetFox; \HV%579
dEJ>8e8
%dKUB4
public class TestMethod { ,=R->~ J
)9l5gZX'I
+^{yJp.H#
public TestMethod() 6ZR'1_i6i=
{ ///xx/weblogic60b2_win.exe +wgNuj0=*
try{ r[JgCj+$&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @$4(!80-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ^t?P32GJ
SiteFileFetch fileFetch = new SiteFileFetch(bean); Ik(TII_
fileFetch.start(); X+ h|sy
} f'TdYG
catch(Exception e){e.printStackTrace ();} 9#@dQ/*
W{?7Pn?1`
%, XyhS5[o
} xmT(yv,
k#w[GL|T
<._MNHC
public static void main(String[] args) }pTy mAN
{ Tmg~ZI:MW
new TestMethod(); AN\:
} F]q pDv
} }2|>Y[v2j
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