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)); 4'',6KJ@
} >OV<_(S4
for(int i=0;i<nEndPos.length-1;i++) nX|Q~x]
{ H@GE)I>^@
nEndPos = nStartPos[i+1]; NUCiY\td
} )l&D]3$6K
nEndPos[nEndPos.length-1] = nFileLength; Hou*lCA
} t8QRi!\=
} @5xu>gKn
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iv*V#J>
//启动子线程 .}q]`<]ze
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ;f:gX`"\
for(int i=0;i<nStartPos.length;i++) +Mk#9r
{ }Z\wH*s`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l<(cd,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >!L&>OOx
nStartPos,nEndPos,i); [E7MsX
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); d+;gw*_Ei
fileSplitterFetch.start(); 8-m 3e
} K/txD20 O|
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~2@Lx3t$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (9 sIA*,}
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", jNA1O68N
nEndPos = " + nFileLength); 4:7mK/Z
// fileSplitterFetch[nPos.length-1].start(); {^#2=`:)O
?c]n^GvG
Tzzq#z&F
//等待子线程结束 Ytao"R/
//int count = 0; d|XmasGN
//是否结束while循环 kZLMtj-
boolean breakWhile = false; 4U=75!>
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dH\XO-Z7v
while(!bStop) >O#grDXb
{ 24ux
write_nPos(); 2?W7I/F
Utility.sleep(500); 5rb-U7 /
breakWhile = true; 9'nH2,_
Gh}yb-$N`&
o:"anHs
for(int i=0;i<nStartPos.length;i++) 9xFO]Y"
{ Pao%pA.<
if(!fileSplitterFetch.bDownOver) Ye5jB2Z
{ wG1l+^p
breakWhile = false; Ts9ktPlm
break; WkP +r9rT
} DIaYo4
} \}5p0.=
if(breakWhile) d,0 }VaY=D
break; a^t?vv
H6K`\8/SeN
)}MHx`KT2
//count++; s =Umj'1k
//if(count>4) ?<U{{C
// siteStop(); wJeG(h
} Md,pDWb
S{#cD1>.
maNW{"1
System.err.println("文件下载结束！"); 8 TiG3
} P:C2G(V1AR
catch(Exception e){e.printStackTrace ();} -oyO+1V
} bc I']WgB-
HpVjee
$g10vF3
//获得文件长度 D\1k.tI
public long getFileSize() kM/Te{<
{ EpYy3^5d
int nFileLength = -1; 3QXjD/h
try{ [q*%U4qGO
URL url = new URL(siteInfoBean.getSSiteURL()); -.IEgggf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 6/Fzco#N
httpConnection.setRequestProperty("User-Agent","NetFox"); !TKkec8$
1u|V`J)0
*|% ^0#$c
int responseCode=httpConnection.getResponseCode(); B=Ym x2A9]
if(responseCode>=400) c~=B0K-
{ =JS;;PzX[
processErrorCode(responseCode); id^sr Mw
return -2; //-2 represent access is error (;_FIUz0
} MFt*&%,JX
VZy4_v=
?4 S+edX
String sHeader; #]]Su91BA
]y@F8$D!
*Dmx&F=3,5
for(int i=1;;i++) yxt[= C
{ dRi5hC$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); B@y(.
//Utility.log(in.readLine()); _oFs #kW
sHeader=httpConnection.getHeaderFieldKey(i); 2xwlKmI N
if(sHeader!=null) l?8M p$M
{ 5J2=`=FK
if(sHeader.equals("Content-Length")) FV39QG4b4
{ 4|?{VQ
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Oakb'
break; "2?l{4T\
} 23!;}zHp
} j;1-p>z
else hm*cw[#O1x
break; .w?(NZ2~
} 69K{+|
} ->^~KVh&
catch(IOException e){e.printStackTrace ();} N|g;W
catch(Exception e){e.printStackTrace ();} \2 y5_;O
kq=V4-a[
a:TvWzX,
Utility.log(nFileLength); Kl{>jr8B3
6K`c/)
`d]IX^;
return nFileLength; cO2& VC
} 'XrRhF (
4+;$7"fJ
4mjgt<`
//保存下载信息（文件指针位置） Y-mK+12
private void write_nPos() {c?JuV4q?
{ lbdTQ6R
try{ I` K$E/ns
output = new DataOutputStream(new FileOutputStream(tmpFile)); O,2~"~kF
output.writeInt(nStartPos.length); I04jjr:<
for(int i=0;i<nStartPos.length;i++) cF)/^5Z
{ #oeG!<Mn
// output.writeLong(nPos); {66sB{P
output.writeLong(fileSplitterFetch.nStartPos); 2&PPz}Sw
output.writeLong(fileSplitterFetch.nEndPos); iD38\XNMV
} LQ11ba
output.close(); J5p"7bc
} 3.d"rl
catch(IOException e){e.printStackTrace ();} #11NPo9
catch(Exception e){e.printStackTrace ();} Uxfl_@lJ
} TL$EV>Nr
D4Al3fe
`;|5
//读取保存的下载信息（文件指针位置） :<Y}l-x
private void read_nPos() [D-Q'"'A
{ w%AcG~`j!B
try{ KlV:L 4a~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); C?ib_K*
int nCount = input.readInt(); NcOPL\
nStartPos = new long[nCount]; o%{'UG
nEndPos = new long[nCount]; im} ?rY
for(int i=0;i<nStartPos.length;i++) {Gq*e/
{ `1*nL,i
nStartPos = input.readLong(); oI:o"T77sA
nEndPos = input.readLong(); 2~[@_
} &6 s) X
input.close(); `@d<n
} 8$s9(n-_Y
catch(IOException e){e.printStackTrace ();} j"^+oxH
catch(Exception e){e.printStackTrace ();} @vL20O.
} {>LIMG-f
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t^]$!H
private void processErrorCode(int nErrorCode) fkSO( C)
{ 7cAXd#sI
System.err.println("Error Code : " + nErrorCode); E:zF/$tG
} -K,-h[o
]<(]u#g_d
ih,%i4<}6m
//停止文件下载 )VL96did
public void siteStop() !Fo*e
{ NNhL*C[_7
bStop = true; Xs&TJ8a
for(int i=0;i<nStartPos.length;i++) Djk C
fileSplitterFetch.splitterStop(); Uz cx6sw
2%*MW"Q
{oc igR0
} E$9Ys
} t?o,RN:
//负责部分文件的抓取 b|Q)[y]
**FileSplitterFetch.java QB.J,o*XD4
*/ CQel3Jtt.
package NetFox; MMB@.W
mk7&<M
O#wpbrJ
import java.io.*; ,B4VT 96*
import java.net.*; 6sIL.S~c)
PB%-9C0
X[#zCM
public class FileSplitterFetch extends Thread { M8H5K
+^*iZ6{+7
PJxH7|GSi
String sURL; //File URL '(? uPr
long nStartPos; //File Snippet Start Position Hf'G8vW
long nEndPos; //File Snippet End Position D7Y)?Z5A;
int nThreadID; //Thread's ID ?USQlnr:R/
boolean bDownOver = false; //Downing is over G} eUL|S
boolean bStop = false; //Stop identical 8WE{5#oi
FileAccessI fileAccessI = null; //File Access interface 0 a]/%y3V
??TMSH
QL6C,#6
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Kp+CH7I*
{ Rqwzh@}
this.sURL = sURL; ~GE$myUT\p
this.nStartPos = nStart; =@TQ>Qw%b
this.nEndPos = nEnd; #r PP*
nThreadID = id; 7+x? "4
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]9}HEu;1M
} +<,gB $j
NmMIQ@K
;8!Z5H
public void run() %uv?we7
{ u%'\UmE w
while(nStartPos < nEndPos && !bStop) .2J L$"
{ VMoSLFp^R
e><5Pr)
7~#:>OjW
try{ E\gim<]
URL url = new URL(sURL); \{Q?^E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); S+TOSjfis
httpConnection.setRequestProperty("User-Agent","NetFox"); "[}O"LTQ
String sProperty = "bytes="+nStartPos+"-"; V\(:@0"
httpConnection.setRequestProperty("RANGE",sProperty); V]*b4nX7
Utility.log(sProperty); 9qS"uj
uKgZ$-'
XZw6Xtn
InputStream input = httpConnection.getInputStream(); JdZ+Hp3.
//logResponseHead(httpConnection); P0`Mdk371
Y(.OF Q
6<K6Y5<6
byte[] b = new byte[1024]; 4v[~r1!V
int nRead; g$. \
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @( n^T
{ Ltjbxw"Qd
nStartPos += fileAccessI.write(b,0,nRead); `jST
//if(nThreadID == 1) ?\8?%Qk
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); D&HV6#
} i#%aTRKHd6
G,;,D9jO7
EyY.KxCB
Utility.log("Thread " + nThreadID + " is over!"); wP,JjPUt
bDownOver = true; fDx9iHGv
//nPos = fileAccessI.write (b,0,nRead); Mi~(aah
} +cU>k}
catch(Exception e){e.printStackTrace ();} qRbf2;
} ;gC|
} |yo\R{&6
V.wqZ {G
64:fs?H
//打印回应的头信息 $%VuSrZ&
public void logResponseHead(HttpURLConnection con) Qp`gswvE
{ U-n;xX0=
for(int i=1;;i++) 0ZQ'_g|%
{ ktDC/8
String header=con.getHeaderFieldKey(i); d GP*O
if(header!=null) Wu)>U
//responseHeaders.put(header,httpConnection.getHeaderField(header)); R *F l8
Utility.log(header+" : "+con.getHeaderField(header)); jD7NblX
else d#2$!z#
break; 'l,V*5L
} u^029sH6j
} ePIiF_X
_=|vgc
l7De6A"
public void splitterStop() :x_'i_w
{ IHRGw
bStop = true; kA7mLrON
} IKie1!ZU{"
J*9$;
bTQNb!&
} Ytgj|@jsp
aZbw]0q@o
l3 DYg
/* }B~If}7
**FileAccess.java svXR<7)#
*//文件访问(定位，写) /PsnD_s]5
package NetFox; }jill+]
import java.io.*; A=Ss6-Je
^_lzZOhG
?.Pg\ur
public class FileAccessI implements Serializable{ =/\:>+p^.y
QNDHOo>v
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9(":,M(/o
RandomAccessFile oSavedFile; {&Q9"C
long nPos; <id}<H
1{P'7IEj
tnLAJ+-M
public FileAccessI() throws IOException GRY2?'`
{ $/nY5[
this("",0); |^@dFOz
} 0?>dCu\
c&L"N!4z
d:yqj:
public FileAccessI(String sName,long nPos) throws IOException ~Ch+5A;
{ *}8t{ F@k
oSavedFile = new RandomAccessFile(sName,"rw"); W0}B'VS.I
this.nPos = nPos; puT'y
oSavedFile.seek(nPos); 8mQmi`
} MTUn3;c/
6d+p7x
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public synchronized int write(byte[] b,int nStart,int nLen) Uk\Id~xLV
{ H<1WbM:w
int n = -1; S6[v;{xJ
try{ >|;aIa@9
oSavedFile.write(b,nStart,nLen); EAeqLtFqs
n = nLen; |<O9Sb_
} t:fFU1x
catch(IOException e) ~RWktv
{ *&f$K1p
e.printStackTrace (); "9n3VX)
} /@|/^vld
f^VP/rdg
KgR<E
return n; 8n>9;D5n
} im @h -A]0
+5XpzZ{#Wa
/B}lO0]:
} q/n,,!
Z> r^SWL
5#K4bA
/* ^+g$iM[`f
**SiteInfoBean.java jRL<JZ1N
*/ H#ncM~y*
package NetFox; L5,NP5RC
P@FHnh3}Z$
-{ZWo:,r~q
public class SiteInfoBean { 0tU.(
QV\eMuNy
QVtQx>K`
private String sSiteURL; //Site's URL a1@Y3MQ;i
private String sFilePath; //Saved File's Path %HJK;
private String sFileName; //Saved File's Name NC38fiH_N
private int nSplitter; //Count of Splited Downloading File 7.`fJf?
db6mfxi
1/"WD?a
public SiteInfoBean() I(XOE$3
{//nSplitter的缺省值为5 h*v8#\b$J_
//default value of nSplitter is 5 H*)NLp
this("","","",5); ]9@F~)
} N ,z6y5Lu
>vA2A1WhW
Jkek-m
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) pxa(
{ ghRVso(
sSiteURL= sURL; F>rH^F
sFilePath = sPath; e2A-;4?_
sFileName = sName; k5T,990
this.nSplitter = nSpiltter; /3{b%0Aa
hvaSH69*m
(P$H<FtH
} hodgDrmO/
|vw"[7_aS
/gG"v5]
public String getSSiteURL() )-._FOZ6
{ O<V4HUW
return sSiteURL; ^(FdXGs[
} v;ZA4c
d m`E!R_
@<x*.8
public void setSSiteURL(String value) *IM;tD+7Q~
{ )>Yu!8i
sSiteURL = value; .p(T^ m2A*
} is-7 j7;
*I0T{~
y_?Me]
public String getSFilePath() z5YWt*nm
{ -jiG7OL
return sFilePath; OtNd,U.dE
} 1 9CK+;b
n<u $=H
X)% A6M
public void setSFilePath(String value) [D4Es
{ >j QWn@
sFilePath = value; J7g8D{4
} \QCJ4}\CS
.yEBOMNZ
7yh/BZ1
public String getSFileName() aSnFKB
{ [;J>bi;3N
return sFileName; @ rc{SB
} %B.yW`,X
%xyou:~0zs
b"{'T]"*j
public void setSFileName(String value) N=7pK&NHSG
{ k-^mIJo}
sFileName = value; 5f 5f0|ok
} 6g)GY"49
,JQp'e
]'=)2 .}
public int getNSplitter() W}mn}gTQ
{ >: g3k
return nSplitter; 6l:qD`_
} D-._z:_
+O?KNZ
=7m)sxj]w
public void setNSplitter(int nCount) ~o~!+`@q
{ pWJFz-
nSplitter = nCount; V: TM]
} ^0\
} Y<%@s}zc
@/ohg0
P&^;656r
/* wLnf@&jQ%
**Utility.java 9eQxit7
*/ dx@-/^.
package NetFox; m()RU"WY
2HsLc*9{4
,tu.2VQc@
public class Utility { |$ lM#Ua
@X;!92i
/k,-P
public Utility() kZGRxp9
{ Tq[kl'_
0i\M,TNf*
-^hWM}F
} EZ`te0[
BdH-9n~,
//线程睡眠 3!|;iJRH
public static void sleep(int nSecond) ud'-;W
{ DrY:9[LP
try{ ]Hefm?9*^
Thread.sleep(nSecond); j~jV'f.:H
} =*c7i]@}
catch(Exception e) .7avpOfz
{ #PH~1`vl
e.printStackTrace (); IS&ZqE(`e
} Ssou
} dQA'($
9CWezI+
//日志 )9"_J9G
public static void log(String sMsg) 1e{IC=
{ ,NyY>~+
System.err.println(sMsg); Gsq00j &<Z
} 2Ay*kmW
tnN.:%mZ
>\P@^ h]
public static void log(int sMsg) wc}5m Hs
{ E%,^Yvh/
System.err.println(sMsg); !W}9no
} afuOeZP
} o.!~8mD
7`zHX&-W
?IqQ-C)6D
/* %4,O 2\0?&
**TestMethod.java bU2Z[sn.
*/ ][+#;avU
package NetFox; 5A3xVN=
26I_YL,S
RL@VSHXc
public class TestMethod { i%#+\F.&
[ 0KlC1=
xy/`ZS2WPq
public TestMethod() {E9+WFz5
{ ///xx/weblogic60b2_win.exe }J:U=HJ
try{ :~tAUy":_*
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #FCnA
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); t!W(_8j
SiteFileFetch fileFetch = new SiteFileFetch(bean); CUBEW~X}M
fileFetch.start(); :OhHb#D
} ^6MU 0Q2
catch(Exception e){e.printStackTrace ();} p'*>vk
G\Cp7:j}
vgH3<pDiU6
} mGJKvJF
6;\I))"[
(a.z9nqGA
public static void main(String[] args) w[zjerH3
{ =hC,@R>;
new TestMethod(); 93("oBd[s(
} [65`$x-
} ~962i#&4
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