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)); //BJaWq
} [|oG}'Xz
for(int i=0;i<nEndPos.length-1;i++) 1C{0 R.
{ Si]?4:E7=
nEndPos = nStartPos[i+1]; 7*+CX
} (WC =om
nEndPos[nEndPos.length-1] = nFileLength; [mu8V+8@d4
} tj~r>SRb+
} pNOE KiJ
0*b8?e
,HTwEq>-G
//启动子线程 kD)31P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mMwV5\(
for(int i=0;i<nStartPos.length;i++) pI-Qq%Nwt
{ x5uz$g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), X^N6s"2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), xOKJOl
nStartPos,nEndPos,i); Z9$pY=8^?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @2hhBW
fileSplitterFetch.start(); W9Azp8)p]
} lf>d{zd5
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 81x/bx@L%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); >^Wpc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", >W] Wc4\
nEndPos = " + nFileLength); \O"H#gt
// fileSplitterFetch[nPos.length-1].start(); m`-:j"]b$
=K}Pfh
PL&>pM
//等待子线程结束 pLCj"D).M
//int count = 0; j!i*&
//是否结束while循环 8xAIn>,_
boolean breakWhile = false; M?sax+'
aC2Vz9e
"zJxWXI
while(!bStop) OP=brLGu0
{ x}K|\KXy
write_nPos(); HJN GO[*g
Utility.sleep(500); 1?H; c5?d&
breakWhile = true; NzyEsZ]$
"=s}xAM|A
pP":,8Q{
for(int i=0;i<nStartPos.length;i++) ^g6v#]&WA
{ KJoa^e;~
if(!fileSplitterFetch.bDownOver) hbJy<e1W
{ =t-Ud^3
breakWhile = false; yg'CL/P
break; W`9{RZ'
} 9`/e=RL
} gPB=Z!
if(breakWhile) 8iY.!.G#|
break; *Ci&1Mu^Z
Al*=%nY
j1g$LAe
//count++; '+/mt_re=
//if(count>4) 9ns( F:
// siteStop(); fDns r"T
} 4N$Wpx
iu=Mq|t0
)uHat#
System.err.println("文件下载结束！"); [>?|wQy>=
} ];Noe9o
catch(Exception e){e.printStackTrace ();} faRQj:R8
} @-S7)h>~
:2c(.-[`
N\ Mdia
//获得文件长度 4h!yh2c..
public long getFileSize() u;nn:K1QFr
{ 8Gy]nD
int nFileLength = -1; 2EpQ(G J
try{ vzI>:Bf
URL url = new URL(siteInfoBean.getSSiteURL()); i=n;rT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); liPrxuP`
httpConnection.setRequestProperty("User-Agent","NetFox"); $!9U\Au>2
A}9^,C$#
3l~7
int responseCode=httpConnection.getResponseCode(); >g!$H}\
if(responseCode>=400) n]#YL4j
{ <Rw2F?S~)n
processErrorCode(responseCode); kYkA^Aq
return -2; //-2 represent access is error +1cr6a
} N<<wg{QO
#@BhGB`9Qt
GPh;r7xg6
String sHeader; ]SA/KV
6)YckxN^
!1R?3rVQS
for(int i=1;;i++) ?SYmsaSr5
{ ,x&WE@tD|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); W#g!Usf:/
//Utility.log(in.readLine()); I_8 n>\u
sHeader=httpConnection.getHeaderFieldKey(i); }o!b3*#
if(sHeader!=null) WP\kg\o
{ j7g>r/1eE
if(sHeader.equals("Content-Length")) 7CR#\&h`
{ +pq=i
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ,|$1(z*a{c
break; $bMmyDw
} dRzeHuF92
} Z:h'kgG&
else \PN*gDmX
break; <Ffru?o4j
} e/g9r
} 6bj77CoB
catch(IOException e){e.printStackTrace ();} qmnl
catch(Exception e){e.printStackTrace ();} aOinD
r\fkx>
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Utility.log(nFileLength); 4Hf'/%kW
ux^rF
5#f_1 V
return nFileLength; jt6_1^
} 9wfE^E1
?Mo)&,__
F#9^RA)9
//保存下载信息（文件指针位置） :&&s*_
private void write_nPos() 5,4" CF$
{ J(]b1e
try{ v\9f 8|K
output = new DataOutputStream(new FileOutputStream(tmpFile)); *\:sHVyG(
output.writeInt(nStartPos.length); a6h+?Q7uF
for(int i=0;i<nStartPos.length;i++) `j'1V1
{ |AExaO"jk
// output.writeLong(nPos); k fY;
output.writeLong(fileSplitterFetch.nStartPos); 3jfAv@I~
output.writeLong(fileSplitterFetch.nEndPos); KIY`3Fl09
} +pK35u
output.close(); t; #@t/`
} \ 6taC
catch(IOException e){e.printStackTrace ();} It2:2
catch(Exception e){e.printStackTrace ();} >f&L7@
} \uo{I~Qd
Zr6.Nw
g*_n|7pB
//读取保存的下载信息（文件指针位置） }vP(SF6
private void read_nPos() O`_, _
{ )j}#6r
try{ mIrN~)C4\
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); FnOahLS
int nCount = input.readInt(); >U\P^yU
nStartPos = new long[nCount]; ]T5\LNyN
nEndPos = new long[nCount]; |DsT $~D
for(int i=0;i<nStartPos.length;i++) Dh}d-m_5
{ Uv<nJM
nStartPos = input.readLong(); _@)-#7
nEndPos = input.readLong(); ^u90N>Dvq
} q3v5gz^t
input.close(); ntPX?/
} ^XYK }J
catch(IOException e){e.printStackTrace ();} +>yh`Zb
catch(Exception e){e.printStackTrace ();} yoieWnL}
} <7Yh<(R e^
keQRS+9
t<}N>%ZO
private void processErrorCode(int nErrorCode) k=p[Mlic/
{ t5 ^hZZ
System.err.println("Error Code : " + nErrorCode); rR{KnM
} CO,{/
gE*7[*2?t
zFYzus`>
//停止文件下载 'O2/PU2_
public void siteStop() f#I#24)RH
{ yZoJD{'?Sw
bStop = true; ON>l%Ae4G
for(int i=0;i<nStartPos.length;i++) .n.N.e
fileSplitterFetch.splitterStop(); |eye) E:
f*xv#G
KT(v'KE 1
} iN0'/)ar
} :T@} CJ
//负责部分文件的抓取 )Xt#coagS
**FileSplitterFetch.java N3KI6p6\
*/ hhU\$'0B-
package NetFox; 5}5oj37x
64"DT3:
}=gD,]2x8
import java.io.*; C(>g4.-p8
import java.net.*; h'vBWtMa
=l] lwA-
Ed_Fx'
public class FileSplitterFetch extends Thread { 5~[][VV^
[T[]U
5V/]7>b1
String sURL; //File URL ,|#biT-<T
long nStartPos; //File Snippet Start Position @0tX,Z9
long nEndPos; //File Snippet End Position i3L2N~:V
int nThreadID; //Thread's ID +4qR5(W
boolean bDownOver = false; //Downing is over f}.t
boolean bStop = false; //Stop identical H|`D3z.c
FileAccessI fileAccessI = null; //File Access interface ^e\$g2).
9R-2\D]
"8a ?KQ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ~`$P-^u88X
{ G~_D'o<r
this.sURL = sURL; %SCt_9u
this.nStartPos = nStart; /#t::b+>x
this.nEndPos = nEnd; 1@TL>jq
nThreadID = id; /&czaAR-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 m' |wlI[lq
} >-3>Rjo>
tU!Yg"4Q
fb[lL7
public void run() Zrgv*
{ @1bl<27
while(nStartPos < nEndPos && !bStop) G%!i="/9
{ {}RU'<D
{z;K0
0#m=76[b
try{ NP4u/C<
URL url = new URL(sURL); f1U8 b*F<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ff =%eg]
httpConnection.setRequestProperty("User-Agent","NetFox"); VKlC`k8L
String sProperty = "bytes="+nStartPos+"-"; ]vV)$xMX
httpConnection.setRequestProperty("RANGE",sProperty); VH+3o?nrT
Utility.log(sProperty); w7q6v>
E1w8d4P,G
|S<!'rY
InputStream input = httpConnection.getInputStream(); gg#lI|
//logResponseHead(httpConnection); ~oK0k_{~
+nB0O/m'U
RHbbj}B
byte[] b = new byte[1024]; ;v.J D7
int nRead; r%$\Na''
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 0$=U\[og
{ ]HXHz(?;F
nStartPos += fileAccessI.write(b,0,nRead); Oc.8d<
//if(nThreadID == 1) TnKOr~@*
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ) jM-5}"
} >r}?v3QW
.*W7Z8!e
>@-.rkd(
Utility.log("Thread " + nThreadID + " is over!"); J!3;\
bDownOver = true; hl)jE 06
//nPos = fileAccessI.write (b,0,nRead); XW^Pz(
} _[l&{,
catch(Exception e){e.printStackTrace ();} i],~tT|P
} uz20pun4B
} z_A\\
bTAY5\wB
,C_MB1u
//打印回应的头信息 ,K30.E
public void logResponseHead(HttpURLConnection con) OJM2t`}_t
{ 9q[[ ,R
for(int i=1;;i++) B|M@o^Tf
{ \CS4aIp
String header=con.getHeaderFieldKey(i); j+gh*\:q
if(header!=null) xbHI4A"Z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); X%B$*y5
Utility.log(header+" : "+con.getHeaderField(header)); e5;YY
else +br' 2Pn
break; FlrYXau
} #e@[{s7
} 5'w&M{{9
OCCC' k
+t Prqv"(
public void splitterStop() vD/l`Ib:
{ 1g$xKe~]4
bStop = true; 'L{pS-+6
} &wu1Zz[qcz
Y$./!lVY
^\\9B-MvY
} =`CK`x
#i.BOQxS
gt~u/Z%
/* *;F<Q!i&v
**FileAccess.java LFYSur8
*//文件访问(定位，写) WZTv
package NetFox; '[_.mx|cd`
import java.io.*; FBzsM7]j
a6It1%a+
f%[xl6VE;
public class FileAccessI implements Serializable{ n 1^h;2gz
Ruwp"T}mF
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 zh(=kS`
RandomAccessFile oSavedFile; '9&@?P;
long nPos; <'hoN/g
P^lzbWj^
Bw[#,_
public FileAccessI() throws IOException zQu9LN
{ #%#N.tB5
this("",0); ]ZI@?H? O
} )g]A 'A=
V<PH5'^$j
j*GS')Cm
public FileAccessI(String sName,long nPos) throws IOException KO"+"1 .
{ !i@A}$y
oSavedFile = new RandomAccessFile(sName,"rw"); WK#%G
this.nPos = nPos; 9gIim
oSavedFile.seek(nPos); SFFJyRCz
} E4_,EeC#
cw0uLMqr`
DC_k0VBn
public synchronized int write(byte[] b,int nStart,int nLen) :TV`uUE
{ LA/Qm/T
int n = -1; QXy=|
try{ ~9;udBfwF
oSavedFile.write(b,nStart,nLen); tk:G6Bkid
n = nLen; wMCgLh\wi
} hx:^xW@r4P
catch(IOException e) hC]:+.Q+
{ ?k^m|Z
e.printStackTrace (); X_,R!$wbg:
} (FGHt/!
V<ilv<
S5UQ
return n; GE!p
} WU,b<PU &
axN\ZXU
C!6D /S
} |=:hUp Jp
r;wm`(e
l%2 gM7WMY
/* n5tsaU;
**SiteInfoBean.java (W[]}k;
*/ Y&DoA0/y
package NetFox; # |OA>[
s<3M_mt
q; C6ID`
public class SiteInfoBean { OF-g7s6VH
slP>;
HoeW6UV
private String sSiteURL; //Site's URL 3Lv5>[MnN
private String sFilePath; //Saved File's Path S{{wcH$n'i
private String sFileName; //Saved File's Name :1]J{,VG
private int nSplitter; //Count of Splited Downloading File 1vJj?Uqc
|PGTP#O<
95ix~cH3q
public SiteInfoBean() EDF0q i
{//nSplitter的缺省值为5 .%M80X{5~
//default value of nSplitter is 5 <l eE.hhf.
this("","","",5); .CW,Td3f!
} _E/
"2 :zWh7|
yOk{l$+
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2a 7"~z~
{ /^X)>1)j
sSiteURL= sURL; -%V~1
sFilePath = sPath; <B @z>V
sFileName = sName; PO:sF]5
this.nSplitter = nSpiltter; !>GDp>0
jQBn\^w
HLc3KYIk
} <$K7f
f=8{cK0j
lW4 6S
public String getSSiteURL() i4M%{]G3Y
{ Ies` !W^
return sSiteURL; \#F>R,
} 5%@~"YCo
\H1t<B,
Tiimb[|
public void setSSiteURL(String value) #GUD^#Jh
{ ]AN%#1++U
sSiteURL = value; wb##|XyK<c
} nAX/u[
GBT219Z@8
(''w$qq"D
public String getSFilePath() 7=qvu&{
{ VM;vLUu!e
return sFilePath; 3[ xHY@c
} /R>YDout}
BE54L+$p
' hdLQ\J
public void setSFilePath(String value) Ua~8DdW
{ 7d+0'3%
sFilePath = value; /1Ss |.
} N0 mhgEA
<KI>:@|Sc
:EH>&vm
public String getSFileName() us.IdG
{ O.-A)S@
return sFileName; kX)*:~*
} 0+.<BOcW5
Xc~BHEp
5Y@Hb!5D
public void setSFileName(String value) O]@s`w
{ IfY?P(P
sFileName = value; o5m]Gqa
} P5GV9SA
Rh)%;
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public int getNSplitter() `L!L=.}4
{ :z%Zur+n c
return nSplitter; $P2*qpqy
} tC.etoh
$0+&xJVn
}U%T6~_wR
public void setNSplitter(int nCount) c}H}fyu%n
{ BbPRPkV
nSplitter = nCount; K1&t>2=%
} V=YDqof
} gN*b~&G
{xICR ~,*
l j+p}dt
/* m9\~dD
**Utility.java Zb'a+8[
*/ H;ujB \+
package NetFox; j8^zE,Z
. K_Jg$3
1{1mL-I;
public class Utility { ['3E'q,4&
#nmh=G?\Sm
bkrl>Im<n
public Utility() . +,{|){c
{ CdtCxy5
+6^hp-G7
6 B7F
} mXyg\5
q%,y66pFr
//线程睡眠 ~ftR:F|9
public static void sleep(int nSecond) ]3Jb$Q@
{ C^:{y
try{ ~4xn^.w
Thread.sleep(nSecond); ,|j\x
} KTeR;6oZn"
catch(Exception e) k`s_31<
{ 0n={Mb
e.printStackTrace (); 90ov[|MkM
} r"t,/@`n
} bw!*=<
`(6cRT`Wp
//日志 h8;H<Y;yQ
public static void log(String sMsg) 7|o}m}yVx
{ *?>52 -&b
System.err.println(sMsg); ih|&q
} ,vBB". LY'
zz8NBO
z(#dL>d$'
public static void log(int sMsg) n;~'W*Ln0
{ Qo*OC 9E`
System.err.println(sMsg); s{42_O?,c
} >gl.ILo
} o>&-B.zq
+6n\5+5
9! yDZ<s
/* BL-7r=Z
**TestMethod.java 6_:KFqc W
*/ w{4#Q[
package NetFox; iRM ?_|
&vfeBth
%/SHB
public class TestMethod { v+( P4fS
p4$4;)
`7.$ A U
public TestMethod() =GiN~$d
{ ///xx/weblogic60b2_win.exe phwBil-vUU
try{ Fc|N6I'o
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); #eF k
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); #T8PgmR
SiteFileFetch fileFetch = new SiteFileFetch(bean); `3z6y&dmx
fileFetch.start(); ]?NiY:v
} xS="o
catch(Exception e){e.printStackTrace ();} G'wyH[ d/
$J0o%9K
eQMa9_
} nB}eJD|
PtGFLM9R
ke)<E98DC
public static void main(String[] args) ~3|)[R=+p1
{ N{6-a
new TestMethod(); Q<yvpT(
} t"5ZYa
} R?Ch8mW.!
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