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)); .%y'q!?
} ;>>n#8`
for(int i=0;i<nEndPos.length-1;i++) Th$Z9+()
{ @R}3f6@67
nEndPos = nStartPos[i+1]; 9/!1J
} <#J5.I 1
nEndPos[nEndPos.length-1] = nFileLength; OLPY<ax
} $[}EV(#y
} F~i ~%f,
4(sHUWT
d!w3LwZ
//启动子线程 u7^(?"x
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ~+j2a3rv-{
for(int i=0;i<nStartPos.length;i++) P3`$4p?
{ 0PqI^|!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V y$*v
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 4e/!BGkAS
nStartPos,nEndPos,i); xL1Li]fM!'
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S.4+tf7+
fileSplitterFetch.start(); iMt3h8
} rrr_{d/
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), d|oO2yzWv
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]/kpEx
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", i^e8.zgywF
nEndPos = " + nFileLength); F|{uA/P{
// fileSplitterFetch[nPos.length-1].start(); "!D y[J
=/_uk{
_XT'h;m
//等待子线程结束 $,2T~1tE
//int count = 0; PcEE`.
//是否结束while循环 Yb-{+H8{J
boolean breakWhile = false; zPND$3&'
[nZIV
-&sY*(:n_
while(!bStop) t))MZw&@
{ ;:j1FOj
write_nPos(); HO['o{>BL
Utility.sleep(500); hO&b\#@~
breakWhile = true; CxeW5qc
`:Gzjngc
JC%&d1
for(int i=0;i<nStartPos.length;i++) G~o!u8^;
{ 5LB{b]w7m
if(!fileSplitterFetch.bDownOver) Jn^b}bk t
{ 0W}qp?
breakWhile = false; 9M;t4Um
break; RSe4lw
} h#"$W;(
} G/Nc@XG\
if(breakWhile) r":anR( ;
break; ?9a%g\`?:
F^'$%XKV
YO.+-(
//count++; 8k95IJR1
//if(count>4) 5gtf`ebs/
// siteStop(); +x=)Kp>
} <|4$TH^t
>P:X\5Oj
hK{H7Ey*
System.err.println("文件下载结束！"); 5\MC5us3
} #'q7 x
catch(Exception e){e.printStackTrace ();} Inv`C,$7Q#
} ?' .AeoE-
=K18|Q0m
E{&MmrlL,
//获得文件长度 .a]#AFX
public long getFileSize() -1,0hmn=+
{ /V:9*C
int nFileLength = -1; [K.1 X=O}
try{ Q}|K29Y:p
URL url = new URL(siteInfoBean.getSSiteURL()); 3y6\0|{1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 8rH6L:]S
httpConnection.setRequestProperty("User-Agent","NetFox"); X)[tb]U/Wx
}a||@unr
-p&u=
int responseCode=httpConnection.getResponseCode(); L)bMO8JH~m
if(responseCode>=400) ##=$$1Ki
{ OQ&N]P2p
processErrorCode(responseCode); B6Kl_~gT
return -2; //-2 represent access is error U_(>eVi7F
} qU7_%Z
iCF},W+
Y@0'0
String sHeader; SOhM6/ID2/
e4YP$}_L
)&c#?wx'w
for(int i=1;;i++) :rUMmO-
{ L"|Bm{Run
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )pH+ibR
//Utility.log(in.readLine()); m4 (pMrJ
sHeader=httpConnection.getHeaderFieldKey(i); n?.;*:
if(sHeader!=null) W~/d2_|/
{ CpO_p%P
if(sHeader.equals("Content-Length")) aX^T[
{ mkn1LzE|F
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); j4?Qd0z
break; Bz/Vzc(
} yx5e
} SlG v
else zHb[.ry~
break; t1adS:)s
} e4tIO
} MqnUym
catch(IOException e){e.printStackTrace ();} fz=?QEG
catch(Exception e){e.printStackTrace ();} {siOa%;*
G kjfDY:
172G
Utility.log(nFileLength); eo0-aHs
_-TplGSO=c
$+'H000x
return nFileLength; T+v*@#iJ_
} WFOJg&
HeAXZA,
Io]FDPN
//保存下载信息（文件指针位置） V.P<>~W
private void write_nPos() TlS? S+
{ TVD~Ix
try{ )x|;%.8FX7
output = new DataOutputStream(new FileOutputStream(tmpFile)); -`~qmRpqY
output.writeInt(nStartPos.length); Cg): Q8
for(int i=0;i<nStartPos.length;i++) Af;Pl|Zh[
{ L/"};VI
// output.writeLong(nPos); [Cl0Kw.LD
output.writeLong(fileSplitterFetch.nStartPos); ^HSxE
output.writeLong(fileSplitterFetch.nEndPos); @.e X8~3=
} R&Y_
output.close(); < '5~p$
} HY)xT$/J
catch(IOException e){e.printStackTrace ();} <:v+<)K
catch(Exception e){e.printStackTrace ();} ! I@w3`
} KS$t
_6NUtU
*p}mn#ru-
//读取保存的下载信息（文件指针位置） gF{ehU%
private void read_nPos() v|%41xOsr
{ bmv8nal<Y
try{ !%G]~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 7Jf~Bn
int nCount = input.readInt(); j,M$l mR')
nStartPos = new long[nCount]; *): |WDR
nEndPos = new long[nCount]; |h]V9=
for(int i=0;i<nStartPos.length;i++) fg^25g'_
{ ZRagM'K
nStartPos = input.readLong(); vA/SrX.
nEndPos = input.readLong(); G)Gp}4gV}
} _uQ]I^'D
input.close(); egaX[j r
} =Zq6iMD
catch(IOException e){e.printStackTrace ();} JI"/,fK^
catch(Exception e){e.printStackTrace ();} y&NqVR=
} M~taZt4
/t0L%jJZ
j<t3bM-G
private void processErrorCode(int nErrorCode) :,l7e
{ a: "1LnvR
System.err.println("Error Code : " + nErrorCode); SyvoN,;Q
} PM\Ju]
0|P=S|%~
FU3K?A B
//停止文件下载 .k,j64 r
public void siteStop() (C!p2f
{ V?u#WJy/
bStop = true; d&#_t@%
for(int i=0;i<nStartPos.length;i++) v~nKO?{
fileSplitterFetch.splitterStop(); E\[BE<y
3oCI1>k
o1.~g'!^
} ${ {4L?7
} +U oNJ
//负责部分文件的抓取 o<Zlm)"%1
**FileSplitterFetch.java | &X<-
*/ 3Vk8'
package NetFox; U]3!"+Y1P
pbVL|\oB}
54_}9_g
import java.io.*; }'oU/@yG
import java.net.*; X1^VdJE
TA[%eMvA
WX&IQ@
public class FileSplitterFetch extends Thread { T~[:oil
\O|SPhaIf
7Jn%XxHq
String sURL; //File URL ]Z!Y*v
long nStartPos; //File Snippet Start Position #J[g r_
long nEndPos; //File Snippet End Position C`.YOkpj
int nThreadID; //Thread's ID nrl?<4_
boolean bDownOver = false; //Downing is over ,h*gd^i
boolean bStop = false; //Stop identical uavATnGO{B
FileAccessI fileAccessI = null; //File Access interface AFAg3/
4=yzf
.|,LBc!
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >tM4|w|
{ @;/Pl>$|'G
this.sURL = sURL; ?H=YJK$k
this.nStartPos = nStart; sVFO&|L
this.nEndPos = nEnd; P#O"{+`
nThreadID = id; cE\w6uBR1
fileAccessI = new FileAccessI(sName,nStartPos);//定位 K. ;ev
} t#NPbLZ
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=6sP`:
public void run() G+ /Q!ic
{ ,>j3zjf^
while(nStartPos < nEndPos && !bStop) 7'\.QJ!<
{ 'Ea3(OsuXn
fCY|iO0.t
#w{`6}p
try{ z9o]);dZ
URL url = new URL(sURL); %KQ1{"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); g257jarkMF
httpConnection.setRequestProperty("User-Agent","NetFox"); iuV4xyp
String sProperty = "bytes="+nStartPos+"-"; i 8sv,P
httpConnection.setRequestProperty("RANGE",sProperty); @M'k/jl
Utility.log(sProperty); 9)!Ksg(h
AwJg/VBo)
8SjCU+V
InputStream input = httpConnection.getInputStream(); Id=20og
//logResponseHead(httpConnection); iJTG+gx
4E''pW]8
L=<xTbY
byte[] b = new byte[1024]; Thggas,
int nRead; /uw@o9`~2-
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) j7P49{
{ ~^F]t$rz
nStartPos += fileAccessI.write(b,0,nRead); |O8e;v72g^
//if(nThreadID == 1) D2ggFxqe
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); a ,mgM&yD
} }9@rhW
^%\a,~
,+i^]yF3j
Utility.log("Thread " + nThreadID + " is over!"); nDrRK
bDownOver = true; RZz?_1'
//nPos = fileAccessI.write (b,0,nRead); iA[T'+.Y
} fG2)r
catch(Exception e){e.printStackTrace ();} >{^_]phlb
} !.R-|<2|6
} neEqw+#Z
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( fFrX_K]
//打印回应的头信息 DwBe_h.
public void logResponseHead(HttpURLConnection con) |.; N_i
{ Q 8]X
for(int i=1;;i++) i;HXz`vT7
{ WyV4p
String header=con.getHeaderFieldKey(i); r9f- [wC
if(header!=null) \9+,ynJH8z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); dX?j/M-
Utility.log(header+" : "+con.getHeaderField(header)); G]B0LUT6c
else >\JPX
break; oIrc))j,$
} ckX8eg!f
} L91(|gQP
HG7Qdw2+O
+C=vuR
public void splitterStop() I]ej ]46K
{ L`t786 (M
bStop = true; N<#J!0w
} k7Nx#%xx
oypLE=H
u8"s#%>Ny
} |1wZ`wGZ:L
UB@(r86d
sD3Ts;k
/* }%KQrlbHJl
**FileAccess.java "|6(.S+o
*//文件访问(定位，写) S%RxYJ(
package NetFox; 8mr fs%_
import java.io.*; X}[1Y3~y
ZPf&4#|
!d##q)D f?
public class FileAccessI implements Serializable{ +aL6$
x.gzsd
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 |mhKD#:
RandomAccessFile oSavedFile; oX6Cd:c-
long nPos; wW TuEM
;)rhx`"n
z{R Mb
public FileAccessI() throws IOException ejg!1*H@n
{ J#d,?
this("",0); .UxkTads
} H8HH) ^
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0Y`+L6&UX
public FileAccessI(String sName,long nPos) throws IOException |f}wOkl
{ [?z;'O}y
oSavedFile = new RandomAccessFile(sName,"rw"); ['(qeS@5O
this.nPos = nPos; IlEU6Rs
oSavedFile.seek(nPos); hbXmIst
} >u%Bn\G
@kd$.7Y9
s\.r3U&6
public synchronized int write(byte[] b,int nStart,int nLen) 2zo>`;l
{ c%<81Y=
int n = -1; , wk}[MF
try{ d/NjY[`5+
oSavedFile.write(b,nStart,nLen); 1sUgjyGQ
n = nLen; .WglLUJ:Z
} L<
catch(IOException e) "P5,p"k:)
{ &IQNsJL!e
e.printStackTrace (); r0z8?
} .yDR2sW
CS%ut-K<5M
ZrYRLg
return n; /p-k'387
} @V4nc 'o.
JA >&$h
7\dt<VV
} Sn97DCdk
B4OFhtYE
}T%E;m-
/* 1%@i4
**SiteInfoBean.java gC6Gm':c
*/ yFo8x[
package NetFox; i&HU7mP/
W__$ i<1
UXa%$gwFw
public class SiteInfoBean { B_!S\?}$
Xk^<}Ep)c
"97sH_ ,
private String sSiteURL; //Site's URL f`}u9!jVR
private String sFilePath; //Saved File's Path jp-(n z\
private String sFileName; //Saved File's Name .Sm 8t$
private int nSplitter; //Count of Splited Downloading File RaiYq#X/
{s@&3i?ZiC
LWo)x
public SiteInfoBean() JpQV7}$
{//nSplitter的缺省值为5 lfoPFJ Z
//default value of nSplitter is 5 8yr-X!eF
this("","","",5); tjZS:@3 Z
} 'fb&3
]<},[s
7CT446
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .j!:Hp(z}
{ 2V @ pt
sSiteURL= sURL; @C'qbO{
sFilePath = sPath; nCldH|>5w
sFileName = sName; CJ;D&qo
this.nSplitter = nSpiltter; ~N2 [j
&WbHM)_n
UuJ gB)
} Dhft[mvo
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.>5E 4^$%
public String getSSiteURL() ?AQR\)P
{ C-2#-{<
return sSiteURL; gZ(\/m8Z
} -OQ6;A"#
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public void setSSiteURL(String value) P+p:Ed80
{ ;S2/n$Ju_
sSiteURL = value; CfLPs)\ACm
} q_6<}2m,U
0@!-+}i
R*"zLJP
public String getSFilePath() &'5j!
{ }e1]Ib!
return sFilePath; Oi!uJofW
} ^O5PcV3Eg
EU7mP MxJ
r-}C !aF]
public void setSFilePath(String value) }8'bXG+
{ i/DUB<>p6
sFilePath = value; }5gQ dj[Y
} CIt@xi#I
Cp-p7g0wlg
p-8x>dmP(
public String getSFileName() Daf;; w
{ &W y9%
return sFileName; 2)`4(38
} 0o!Egq_
$T'lWD*
[{-;cpM\
public void setSFileName(String value) K30{Fcb< h
{ 5 .bU2C
sFileName = value; _K>YB>W}7
} ^X?3e1om
JLxAk14lc
SQBe}FlktK
public int getNSplitter() 9r,7>#IF
{ oGZ%w4T
return nSplitter; OEgp!J
} mvW,nM1Y
, rc %#eF
"M:0lUy
public void setNSplitter(int nCount) jTz~ V&^
{ uHO>FM,
nSplitter = nCount; a^GJR]] {
} ]$WwPDZ
} $]]|#}J
<bOi}
$~.'Tnk)
/* >BlF< d`X
**Utility.java n|I5ylt
*/ [[0u|`T/
package NetFox; lxD~[e
LZ*ZXFIg
64-;| k4F
public class Utility { p#(5 ;
nJo6;_MI!
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public Utility() QPpC_pZh
{ S_56!
+(| ,Ke
lK3Z}e*eXQ
} (E?X@d iu
L,wEUI
//线程睡眠 jG&gd<^
public static void sleep(int nSecond) 2_Otv2
{ <-m[0zgq
try{ UgZuEfEGve
Thread.sleep(nSecond); N(^ q%eHp
} ).1F0T
catch(Exception e) P>i[X0UnL
{ YeCS`IXm
e.printStackTrace (); s:\FlQ0
} ;sn]Blpq
} S U$U
ify}xv
//日志 "_T8Km008
public static void log(String sMsg) -}9a%
{ )>|x2q
System.err.println(sMsg); Rz9IjL.Z
} $UGX vCR
W #kOcw
&;Jg2f%.
public static void log(int sMsg) gG6j>%y
{ tjTnFP/=
System.err.println(sMsg); Wc qUF"A
} \_J;i[
} )Cfk/OnRd
%d#h<e|,.
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/* m]#oZVngy
**TestMethod.java UiLiy?EJ
*/ 9d_ Zdc
package NetFox; >Kjl>bq
qmx4hs8sh
Z0I>PBL@l
public class TestMethod { sbi+o,%1
?(d<n
6_wj,7
public TestMethod() 5b5Hc Inu
{ ///xx/weblogic60b2_win.exe :7[20n}w
try{ T@)|0M
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T>2_r6;
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); kI|7o>}<
SiteFileFetch fileFetch = new SiteFileFetch(bean); /l&$B
fileFetch.start(); gONybz6]
} gJC~$/2
catch(Exception e){e.printStackTrace ();} "|KhqV=?v
(AI 4a+
g`9`/
} ev"f@y9Do
rCp'O\@S
}a?(}{z-
public static void main(String[] args) X&14;lu%p
{ #Li6RSeW
new TestMethod(); &kp`1kv":
} t#BQB<GI
} =)mA.j}E2
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