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)); )KVr2y;RF
} 5J|S6x\
for(int i=0;i<nEndPos.length-1;i++) v'b%m8
{ N3aqNRwlk
nEndPos = nStartPos[i+1]; @ =~k[o
} .`5|NUhN
nEndPos[nEndPos.length-1] = nFileLength; |+::sL\r
} qNP)oU92
} N6\rjYx+7
hf0(!C*
jC>#`gD
//启动子线程 D GcpYA.7'
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; qtozMa
for(int i=0;i<nStartPos.length;i++) T!B\ixt6
{ kWVk^,
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), iLNUydiS
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), [ }Tb2|
nStartPos,nEndPos,i); !<HMMf,-D
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); SQn.`0HT
fileSplitterFetch.start(); VjNr<~|d
} Z"_8l3
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }r,xx{.u7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |N"K83_pr
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", W Zm8!Y
nEndPos = " + nFileLength); czpu^BT;;T
// fileSplitterFetch[nPos.length-1].start(); }2"W0ZdWD
DuR9L'
CEaAtAM
//等待子线程结束 E;x-O)(&
//int count = 0; vYb4&VV
//是否结束while循环 Xq03o#-p+
boolean breakWhile = false; 58HA*w
6Aq]I$
!rAH@y.l
while(!bStop) [+pa,^
{ 'TH[Db'`I
write_nPos(); o:W*#dt
Utility.sleep(500); Qg~w 3~
breakWhile = true; s(5hFuyg
;CF:cH*
*pSnEWwE
for(int i=0;i<nStartPos.length;i++) :{iH(ae;
{ !#W>x49}
if(!fileSplitterFetch.bDownOver) ,f>9oOqqA
{ ncOgSj7e
breakWhile = false; l&U$LN$*e
break; 2w8cJadT'p
} w43b=7
} ,52 IR[I<T
if(breakWhile) [f6BA|
break; amC)t8L?
Nc{&AV8Y_v
fxoEK}TM
//count++; :i?6#_2IC
//if(count>4) h8 N|m0W
// siteStop(); Y z&!0Hfd
} d7[^pN
%aMC[i
G$V=\60a-
System.err.println("文件下载结束！"); `x#S.b
} P(b[|QF
catch(Exception e){e.printStackTrace ();} 0RMW>v/7kL
} 43B0ynagN
I[\7Bf
uGb+ *tD
//获得文件长度 lGWz
public long getFileSize() U'(zKqC
{ 9t)Hi qj
int nFileLength = -1; *8?2+)5"
try{ g`S;xs
URL url = new URL(siteInfoBean.getSSiteURL()); hx9t{Zi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); iJ^}{-
httpConnection.setRequestProperty("User-Agent","NetFox"); rZ3ji(4HS
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pgh(~[
int responseCode=httpConnection.getResponseCode(); >4Tk#+%Jj
if(responseCode>=400) DGb1_2ZQ
{ E]/2u3p
processErrorCode(responseCode); .x,y[/[[)
return -2; //-2 represent access is error IJ2'
} {TpbUj0
76@W:L*J$J
CZu=/8?
String sHeader; wzju)qS
XF)N_}X^
1~K'r&
for(int i=1;;i++) Bt}90#
{ jIe /X]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S9}I
//Utility.log(in.readLine()); K'J_AMBL
sHeader=httpConnection.getHeaderFieldKey(i); d9k`
if(sHeader!=null) v9Ii8{ca|
{ pMHl<HH
if(sHeader.equals("Content-Length")) k &J;,)V
{ JfWkg`LqL
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); axvZA:l
break; xCXsyZ2h
} tyW}=xs
} uuwJ-
else }lX$KuD
break; \u[}
} 7AT8QC`u
} R3_OCM_*
catch(IOException e){e.printStackTrace ();} [.xY>\e
catch(Exception e){e.printStackTrace ();} *w(n%f
t :YZua
P8By~f32_
Utility.log(nFileLength); 2hF^U+I}
4>V@+#Ec5
P}5bSQ( a3
return nFileLength; 1mJUlx
} 8b]4uI<
;k`51=Wi
u3O@ccJ;
//保存下载信息（文件指针位置） mih}?oi
private void write_nPos() ,:L^vG@*
{ f<wYJGI
try{ -+1O*L!
output = new DataOutputStream(new FileOutputStream(tmpFile)); )SJM:E
output.writeInt(nStartPos.length); 3 5.&!4}
for(int i=0;i<nStartPos.length;i++) ( `bb1gz
{ $%DoLpE>
// output.writeLong(nPos); j]kgdAq>
output.writeLong(fileSplitterFetch.nStartPos); )GVTa4}p
output.writeLong(fileSplitterFetch.nEndPos); -F`GZ
} NN'pBUR
output.close(); |\uj(|
} l3F$5n
catch(IOException e){e.printStackTrace ();} >YWK"~|i~
catch(Exception e){e.printStackTrace ();} 'pIrwA^6N
} 4PxP*j
N7lg6$s Aj
'a+^= c
//读取保存的下载信息（文件指针位置） {Dl@/fz
private void read_nPos() TxF^zx\
{ K\%\p$ZD
try{ j3-o}6
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); & tT6.@kH
int nCount = input.readInt(); `WL3aI":
nStartPos = new long[nCount]; ~$K{E[^<
nEndPos = new long[nCount]; &v((tZ
for(int i=0;i<nStartPos.length;i++) i*:QbMb
{ rbdrs
nStartPos = input.readLong(); N9G xJ6
nEndPos = input.readLong(); .lb]Xa*n
} K2x2Y=
input.close(); `B3-#!2X
} Izu____
catch(IOException e){e.printStackTrace ();} d"?"(Q_8n
catch(Exception e){e.printStackTrace ();} m85ZcyW1T
} }hg=#*
myX&Z F_9
D8,8j;
private void processErrorCode(int nErrorCode) V;SV0~&
{ S`5bcxI_
System.err.println("Error Code : " + nErrorCode); bi+M28m
} aQL0Sj:,
8Snv, Lb`^
A+Isk{d
//停止文件下载 td%J.&K_*'
public void siteStop() RRS)7fFm
{ D`^wj FF
bStop = true; %/e'6g<
for(int i=0;i<nStartPos.length;i++) AYY(<b
fileSplitterFetch.splitterStop(); yW'{Z]09
[Lje?M* r
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} Nm&'&L%Ch
} *cWHl@4
//负责部分文件的抓取 &PV%=/-J
**FileSplitterFetch.java ${z#{c1
*/ MMKN^a"GA
package NetFox; V1M|p!
OW};i|
meV Z_f/
import java.io.*; +%9Re5R
import java.net.*; b`+yNf
PQlA(v+S
k%~;mu"4}
public class FileSplitterFetch extends Thread { Bq)dqLwk
f:\)! &W
[n/c7Pe
String sURL; //File URL DjK7_'7(L
long nStartPos; //File Snippet Start Position :l]qTCmY
long nEndPos; //File Snippet End Position n.9k5r@
int nThreadID; //Thread's ID 3xz~##
boolean bDownOver = false; //Downing is over W"@'}y
boolean bStop = false; //Stop identical ~fD\=- S1
FileAccessI fileAccessI = null; //File Access interface %,vq@..^
zdPJ>PNU
T;BFO5G@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException LbJf5xdi
{ 2Cy,#X%j>
this.sURL = sURL; e)?}2
this.nStartPos = nStart; +$L}B-F
this.nEndPos = nEnd; m,kYE9{
nThreadID = id; p+?`ru
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l:@=9Fp>
} ,\ 1X\
KNN{2thy `
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public void run() 0/]h"5H3
{ &8i$`6wY
while(nStartPos < nEndPos && !bStop) `~d7l@6F
{ \8ZVI98
A/a=)su
2 ^"j]g>mj
try{ ,(h-
URL url = new URL(sURL); 1ED7.#g
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); IfB .2e`
httpConnection.setRequestProperty("User-Agent","NetFox"); w+')wyB
String sProperty = "bytes="+nStartPos+"-"; YBj*c$.D0
httpConnection.setRequestProperty("RANGE",sProperty); yI|x 5f
Utility.log(sProperty); R%n*wGi_6b
]XlBV-@b
"9[2vdSX
InputStream input = httpConnection.getInputStream(); ;&|I/MVm
//logResponseHead(httpConnection); -`Z!p
1mtYap4
^bPpcm=
byte[] b = new byte[1024]; AEj%8jh
int nRead; :+\sKEzL
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) jcJ@A0]
{ c oZK
nStartPos += fileAccessI.write(b,0,nRead); ,aezMbg
//if(nThreadID == 1) ?QKDYH(
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Zbre5&aU
} whw+
1O0)+9T82
AfO.D?4x
Utility.log("Thread " + nThreadID + " is over!"); T.z efoZ
bDownOver = true; NL|c5y<r
//nPos = fileAccessI.write (b,0,nRead); 7P2(q
} p9G+la~;VM
catch(Exception e){e.printStackTrace ();} Zp[>[1@+
} Ii}{{1N6
} WPr:d
F(/<ADx
ul_E{v
//打印回应的头信息 (p#c p
public void logResponseHead(HttpURLConnection con) &Hf%Va[B
{ ddl]! ^IK
for(int i=1;;i++) CIo`;jt K
{ Kp7)my
String header=con.getHeaderFieldKey(i); X4\T=Q?uLx
if(header!=null) Or$"f3gq
//responseHeaders.put(header,httpConnection.getHeaderField(header)); v]@ XyF\j8
Utility.log(header+" : "+con.getHeaderField(header)); T}?b,hNl$
else T[e+iv<8j
break; sF :pwI5^
} g2?W@/pa
} k t!@}QP
k9H}nP$F
rIB./,
public void splitterStop() on8$Kc
{ /oEDA^qx
bStop = true; n4{?Odrf
} 4IOqSB|
&x*l{s[
l{3zlXk3z
} n?6^j8i
_?felxG[
!Y|xu07
/* )R<93`q
**FileAccess.java ,@p4HN*
*//文件访问(定位，写) ,H?e23G
package NetFox; a 01s'9Be
import java.io.*; 89 m.,
Z3wdk6%:}
!a V:T&6
public class FileAccessI implements Serializable{ N@Ap|`Ei
T:%0i8p
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 >\'}&oi
RandomAccessFile oSavedFile; {%('|(57
long nPos; $!p2Kf>/Q
@Kt!uKrI
tr0kTW$Ad
public FileAccessI() throws IOException =C(BZ+-^
{ r&v!2A]:
this("",0); <x<qO=lq
} J<"Z6 '0v
&a\w+
&'/PEOu&}G
public FileAccessI(String sName,long nPos) throws IOException 3zfiegY@wm
{ ~3Qa-s;g
oSavedFile = new RandomAccessFile(sName,"rw"); leSBR,C
this.nPos = nPos; *h?}~!AjY
oSavedFile.seek(nPos); cRag0.[
} rKOa9M
{='wGx
n]w%bKc-9
public synchronized int write(byte[] b,int nStart,int nLen) @pJ;L1sn
{ X}={:T+6s
int n = -1; `;R$Ji=>
try{ ]{|l4e4P
oSavedFile.write(b,nStart,nLen); w0=/V[fs
n = nLen; \zA3H$Df~
} g=v'[JPd
catch(IOException e) '>bn94$
{ F|VHr@%
e.printStackTrace (); i 28TH Jh
} K",Xe>
v'`qn
%,S:^Rvv
return n; (IHR {m
} F!I9)PSj
(?T{^Hg
N7 _rVcDe
} &C9)%5O)
. Z9c.E{
%qrUP\rn
/* 1"<{_&d1
**SiteInfoBean.java )`|`PB
*/ /a}N6KUi
package NetFox; w9x5IRWk
E6Uj8]P`
z+0#H39&
public class SiteInfoBean { s"tH?m )6
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|a\,([aU
private String sSiteURL; //Site's URL HmsXV_B8[Y
private String sFilePath; //Saved File's Path @YS,)U)4S
private String sFileName; //Saved File's Name RSM+si/
private int nSplitter; //Count of Splited Downloading File m\=Cw&(
RWDPsZC
uE,TEa9;
public SiteInfoBean() ^MhMYA
{//nSplitter的缺省值为5 B/~ubw
//default value of nSplitter is 5 -@'RYY=
this("","","",5); %vG;'_gMB
} $`C$|9S
7D8 pb0`;J
5Ktll~+:#
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) `J{{E,y @
{ @@!]Raj=
sSiteURL= sURL; `B3YP1
sFilePath = sPath; 0+_;6
sFileName = sName; {FC<vx{42
this.nSplitter = nSpiltter; _39VL
F Zt;D
7=wQ#bq"1P
} -s91/|n
Ym-mfWo^#
!;k ^
public String getSSiteURL() [[4!b E
{ 3)^2X
return sSiteURL; zJ8jJFL+Y
} S~g"
$qoal
Y\(?&7Aax
public void setSSiteURL(String value) `RqV\ 6G+
{ 0V2~
sSiteURL = value; p+2%LYR u
} z`dnS]q9
r6:nYyF$)v
8rz,MsFR
public String getSFilePath() D/2;b;-
{ )Z:maz
return sFilePath; OtT*)8*c
} d5W=?
U!lWP#m
R~dWblv
public void setSFilePath(String value) EiA_9%<
{ ar`}+2Qh0
sFilePath = value; 'HWPuWW
} 0+rBGk
@]],H0
M!PK3
public String getSFileName() H Mfhe[A?
{ ^g+M=jq _
return sFileName; ef:Zi_o
} !-B|x0fs
}OgZZ8-_M
*+ O
public void setSFileName(String value) o-AAx#@
{ A1jA$
sFileName = value; V#DNcF~v]f
} evyA#~o
4Rl~7|
v)!^%D
public int getNSplitter() z&|sks7
{ H)+wkR!~
return nSplitter; [lj^lN8
} lR]SGdY
7<F{a"5P
1~*JenV-
public void setNSplitter(int nCount) %bTXu1
{ *&F~<HC2+
nSplitter = nCount; 73E[O5?b
} I9cZZ`vs
} ~0{F,R.$
vqwSOh|P9
G4f%=Z
/* `]l[p+DO
**Utility.java {/qq*0wa
*/ 9q<?xO
package NetFox; YYd!/@|N5
g6q67m<h
"Ze<dB#,Y
public class Utility { @p7*JLO
F[oTc^dr
0^ $6U
public Utility() F:2V;
{ }?%5Ae7l,
n{.SNipU
}{)>aJ
} 0hju@&Aa
AkV8}>G?#A
//线程睡眠 Y/n],(t)
public static void sleep(int nSecond) '$be+Z32
{ =MMSmu5!
try{ <o_(,,P%
Thread.sleep(nSecond); :#spL*FIx
} h@(S];.
catch(Exception e) P:HmT
{ dmE.yVI"O
e.printStackTrace (); ?(j:F2dU~
} r(/+- t
} Lc13PTz>>g
l0{R`G,
//日志 k/lDE
public static void log(String sMsg) UxVxnJ_
{ +S}/6dg
System.err.println(sMsg); ^y&sKO
} 1bJrEXHXy
| D,->k
i}e OWi
public static void log(int sMsg) x-=qlg&EI
{ dy2<b+..
System.err.println(sMsg); SH M@H93
} <bgFc[Z
} 6 VuMx7W1
$"x~p1P
=!|=Y@
/* '"Y(2grP
**TestMethod.java HFrwf{J
*/ JG!@(lr
package NetFox; ir3EA'_>N
G![JRJxQ
SW_jTn#x
public class TestMethod { x1R<oB|
\#)w$O
Oi4tG&q
public TestMethod() 5IiZnGu
{ ///xx/weblogic60b2_win.exe 6.gk6
try{ dgM@|&9*m
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 4z>SI\Ss
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 924a1
SiteFileFetch fileFetch = new SiteFileFetch(bean); H)O I&?
fileFetch.start(); yMbg1+:
} ;*XH[>I
catch(Exception e){e.printStackTrace ();} VRa>bS
|jE0H!j
8P3"$2q
} =F"vL
z;ko )
eUE(vn#
public static void main(String[] args) ,fW%Qv
{ C{8(ew
new TestMethod(); z1 P=P%F
} P+t`Rw
} Ov PTgiI!N
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