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)); )OHGg
} U45kA\[bZ
for(int i=0;i<nEndPos.length-1;i++) :'`y}'
{ iq^F?$gFk
nEndPos = nStartPos[i+1]; }TQa<;Q
} Upw`|$1S
nEndPos[nEndPos.length-1] = nFileLength; 0\zY?UUww
} )DB\du
} BTc }Kfae
Oh# z zo
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//启动子线程 )_n=it$
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; &cGa~#-u
for(int i=0;i<nStartPos.length;i++) ?}RPnf
{ +>3jMs~&
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), [s4|+
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), tn{YIp
nStartPos,nEndPos,i); :a/l9 m(
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); bog3=Ig-
fileSplitterFetch.start(); 3_bqDhVI5
} hsB3zqotF
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), `%A vn<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]A%]W^G
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", fn#qcZv?
nEndPos = " + nFileLength); CY~ S{w
// fileSplitterFetch[nPos.length-1].start(); t"JE+G
"7q!u,u
GJ5R <f9I
//等待子线程结束 s Poh\n
//int count = 0; n&l(aRoyx
//是否结束while循环 ?wP/l
boolean breakWhile = false; `=V p 0tPI
k?Kt*T
/q,vQ[R/
while(!bStop) D%}rQ,*
{ t!-\:8n
write_nPos(); ?lE&ow
Utility.sleep(500); Nj;5iy
breakWhile = true; nuH=pIq6x
6(=B`Z}a
fUMjLA|*I<
for(int i=0;i<nStartPos.length;i++) }W)b
{ Jxf>!\:AZu
if(!fileSplitterFetch.bDownOver) W_L*S4 ~
{ w_h{6Kc<
breakWhile = false; cgnMoBIc
break; jB<B_"
} Q5c3C&$6
} !RP0W
if(breakWhile) > ^=n|%
break; ~R&rQJJeJ
qj9[mBkP"
U&i#cF
//count++; {]bmecz
//if(count>4) Y'{}L@"t
// siteStop(); tD*k
} )T6:@n^]h
qt(4?_J
uK]-m
System.err.println("文件下载结束！"); 5dGfO:Dy_
} <2d)4@B=
catch(Exception e){e.printStackTrace ();} Pbd[gKX_
} _@i-?Q
*I!R0;HT
yAAV,?:o[
//获得文件长度 mqHcD8X
public long getFileSize() wPEK5=\4Ob
{ mv>0j<C91
int nFileLength = -1; mPU}]1*p
try{ Zs(BViTb|
URL url = new URL(siteInfoBean.getSSiteURL()); IsmZEVuC
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); hraR:l D
httpConnection.setRequestProperty("User-Agent","NetFox"); eR4ib-nS
OK)>QGl
wz1nV}
int responseCode=httpConnection.getResponseCode(); -oUGmV_
if(responseCode>=400) #|K{txC
{ tm/=Oc1p
processErrorCode(responseCode); ,4S[<(T"
return -2; //-2 represent access is error t>Ye*eR*`U
} ?N<,;~
Nyt*mbd5 {
~j>yQ%[v
String sHeader; {+zG.1o^
V:#rY5X
gg.]\#3g
for(int i=1;;i++) &#JYh=#
{ 118lb]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); \pk9i+t
//Utility.log(in.readLine()); mKjTJzS
sHeader=httpConnection.getHeaderFieldKey(i); O&MH5^I
if(sHeader!=null) ;O1jf4y
{ LofpBO6^
if(sHeader.equals("Content-Length")) b}fC' h
{ BYu(a
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >|, <9z`D
break; P4HoKoj2`
} 7m ou
} vp2w^/])u
else 0Ix,c(%
break; )u+O~Y95&i
} k,$/l1D
} |fywqQFq
catch(IOException e){e.printStackTrace ();} qH0JZdk
catch(Exception e){e.printStackTrace ();} %X's/;(Lx`
sBYDo{01
JN:L%If
Utility.log(nFileLength); ^\g.iuE
yH=<KYk
6/#+#T
return nFileLength; '%4fQ%ID}
} W**[:n+
}-sh
SOE-Kio=B
//保存下载信息（文件指针位置） =xDxX#3
private void write_nPos() %19~9Tw
{ pdm(7^
try{ ,}\LC;31,
output = new DataOutputStream(new FileOutputStream(tmpFile)); ^SsdM#E
output.writeInt(nStartPos.length); U#[T!E
for(int i=0;i<nStartPos.length;i++) +pq) 7
{ z6}p4
// output.writeLong(nPos); p7 !y#
output.writeLong(fileSplitterFetch.nStartPos); *#E_KW1RV
output.writeLong(fileSplitterFetch.nEndPos); [Rub
} 4i.&geXA.
output.close(); @54$IhhT~
} x&^Xgi?
catch(IOException e){e.printStackTrace ();} za}Kd^KeB
catch(Exception e){e.printStackTrace ();} V)Oot|
} V dvj*I
]Tb?z&
xI<B)6D;f
//读取保存的下载信息（文件指针位置） &OZx!G^Z
private void read_nPos() p[o]ouTcS
{ ;zze.kb&F
try{ ]KEE+o
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); [L7s(Zs>
int nCount = input.readInt(); tK[o"?2y
nStartPos = new long[nCount]; lwfM>%%N
nEndPos = new long[nCount]; x1Y/^ks@2
for(int i=0;i<nStartPos.length;i++) @I|kY5'c
{ 4[#)p}V
nStartPos = input.readLong(); @67GVPcxl
nEndPos = input.readLong(); n|?sNM<J3
} OM^`P
input.close(); =$+0p3[r
} wl%ysM|x
catch(IOException e){e.printStackTrace ();} m' S{P:TK
catch(Exception e){e.printStackTrace ();} % >a /m.$
} y`8U0TE3R
Ym"^Ds}
I L7kpH+y
private void processErrorCode(int nErrorCode) Du +_dr^4
{ "=+i~N#Sc
System.err.println("Error Code : " + nErrorCode); K|\0jd)N
} n^$Q^[:Z
0[fBP\H"Wr
@`+\vmfD
//停止文件下载 !~RK2d
public void siteStop() kCEo*/,
{ _VjaTw8iM
bStop = true; #tpz74O
for(int i=0;i<nStartPos.length;i++) @YRy)+
fileSplitterFetch.splitterStop(); 3QKBuo
a * CXg.i
/2E Q:P
} -O,:~a=*_
} S&-F(#CF^
//负责部分文件的抓取 N.+A-[7,W
**FileSplitterFetch.java x^_c4,i)
*/ KztQT9kY
package NetFox; Sh5)36
h5T~dGRlR
0}`.Z03fy
import java.io.*; [_`yy
import java.net.*; !-n*]C
>);M\,1\I
sw}^@0ua=
public class FileSplitterFetch extends Thread { W`u @{Vb]
8%?MRRK
-K$ugDi
String sURL; //File URL pg!oi?Jn
long nStartPos; //File Snippet Start Position 8dLmsk^
long nEndPos; //File Snippet End Position k<j]b^jbz
int nThreadID; //Thread's ID tS\Db'C7
boolean bDownOver = false; //Downing is over A-.Wd7^~*
boolean bStop = false; //Stop identical oiR9NB&<
FileAccessI fileAccessI = null; //File Access interface (pM&eow}
^fsC]9NS
},}g](!m
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException t~dK\>L
{ x!W5'DO
this.sURL = sURL; wj0_X;L
this.nStartPos = nStart; LjEMs\P\
this.nEndPos = nEnd; +:jv )4^O
nThreadID = id; 6Y6t.j0vN.
fileAccessI = new FileAccessI(sName,nStartPos);//定位 w;(=wN\
} q&3(yhx
_*g.U=u
Z8/.I
public void run() _<2{8>EVf
{ AB0}6g^O
while(nStartPos < nEndPos && !bStop) ~.J*_0~Ze
{ 6vTnm4
gaNe\
_,v?rFLE
try{ +t*I{X(
URL url = new URL(sURL); uit.r^8l
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3?`TEw~'
httpConnection.setRequestProperty("User-Agent","NetFox"); ~*\ *8U@7
String sProperty = "bytes="+nStartPos+"-"; "Xwsu8~
httpConnection.setRequestProperty("RANGE",sProperty); G(shZ=fq
Utility.log(sProperty); 3G 5xIr6
(RrC<5"
o(> #}[N}
InputStream input = httpConnection.getInputStream(); Z eY*5m
//logResponseHead(httpConnection); ki2`gLK
.X(qs1
p/u
byte[] b = new byte[1024]; eHGx00:
int nRead; vA ZkT"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) DnhbMxh8o
{ F\&^(EL
nStartPos += fileAccessI.write(b,0,nRead); P.k>6T<U>
//if(nThreadID == 1) Uc,..
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U|.r -$|5P
} [AIqKyIr
9m_~Zs}Z
nQ|($V1?W
Utility.log("Thread " + nThreadID + " is over!"); Y`$\o
bDownOver = true; 50A\Y)i_mZ
//nPos = fileAccessI.write (b,0,nRead); I`jG
} iqB%sIP
catch(Exception e){e.printStackTrace ();} 2!CL8hG5:
} @}waZ?'
} +>2.O2)%q
</5
wL]#]DiE
//打印回应的头信息 snu?+*6
public void logResponseHead(HttpURLConnection con) ,afO\oe>MG
{ @ZJ}lED3
for(int i=1;;i++) |=~mRqG
{ lfd-!(tXD
String header=con.getHeaderFieldKey(i); v$JW7CKA
if(header!=null) v+trHdSBYE
//responseHeaders.put(header,httpConnection.getHeaderField(header)); cUd>ahv
Utility.log(header+" : "+con.getHeaderField(header)); jLO$[c`;
else P|lDW|}D@
break; G;pmR^
} n)D
} 3QVUWhJ
+O8zVWr
u#y)+A2&!
public void splitterStop() T*C F5S
{ 2ve<1+V_
bStop = true; Y[>h |@
} -`z%<)!Y
>o`+j$j
UH+#Nel+!
} qkp0'f*}
$T66%wX
o /1+ }f
/* =WZ9|e
**FileAccess.java j` * bz-
*//文件访问(定位，写) -k2|`t _
package NetFox; ?|}qT05
import java.io.*; 7h41E#
9B83HV4J
:9x]5;ma
public class FileAccessI implements Serializable{ ;.=0""-IF
jA~omX2A
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 SdMLO6-
RandomAccessFile oSavedFile; cH|J
long nPos; 7i02M~*uS
'^7UcgugB
'"LaaTTs
public FileAccessI() throws IOException hcYqiM@8>
{ d1t_o2
this("",0); xb9^WvV
} 4f~q$Sf]<
lg ,%
Y$)y:.2#
public FileAccessI(String sName,long nPos) throws IOException aM#xy6:XG
{ JX&%5sn(
oSavedFile = new RandomAccessFile(sName,"rw"); v^p* l0r6:
this.nPos = nPos; `C-8zA
oSavedFile.seek(nPos); :=!6w
} q;f L@L@-
'gD./|Z0
[]yIz1P=j
public synchronized int write(byte[] b,int nStart,int nLen) 28+{
{ `fJ;4$4
int n = -1; +<V$G/"
try{ BNr%Q:Q
oSavedFile.write(b,nStart,nLen); 2VX9FDrnk
n = nLen; 60e{]}Z
} DR]oK_
catch(IOException e) d$E>bo-\
{ 0a@tPskV
e.printStackTrace (); z.2UZ%:
} rxJl;!7G
S+mBVk"-~S
I1dOMu9
return n; Q[H4l({E
} s,/C^E
;<+Z}d/g9
4R8Qn^
} --c)!Vxzx
LtKR15h,
*J':U>p
/* gA1j'!\6l9
**SiteInfoBean.java \S?-[v*{
*/ 8 K)GH:a
package NetFox; 6e5A8e8"]
w_~tY*IwB
=1)9>=}
public class SiteInfoBean { oz|+{b}%
}"%mP 4]&
< %<nh`D
private String sSiteURL; //Site's URL ~% `hh9]
private String sFilePath; //Saved File's Path 9ku|w#%I
private String sFileName; //Saved File's Name vtK.7AF
private int nSplitter; //Count of Splited Downloading File V;)+v#4{
L7xiq{t`Y
k{|>!(Ax
public SiteInfoBean() h:FN&E c}
{//nSplitter的缺省值为5 R]>0A3P
//default value of nSplitter is 5 d:cOdm>,
this("","","",5); GlJOb|WOX
} Dd, &a
XI`s M~'
B_8JwMJu3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2'Kh>c2
{ jSdC1,wR
sSiteURL= sURL; v9f%IE4fX
sFilePath = sPath; q8GCO\(
sFileName = sName; 9 *v14c%
this.nSplitter = nSpiltter; 3{ea~G)[9
pwV~[+SS_
N1"bH~
} Zqb*-1Qw"*
x{/-&`F
bH!_0+$P
public String getSSiteURL() -z%->OUu
{ _nSEp>]L
return sSiteURL; tTh4L8fO
} G3h"Eo?>g
;Eh"]V,e
6P)DM
public void setSSiteURL(String value) Xe(]4Ux
{ p&D7&Sb[
sSiteURL = value; "~Zdv}^xS
} :)h4SD8Y
:z6?
MM( ,D& Z
public String getSFilePath() x'SIHV4M@Q
{ GB,ub*|
return sFilePath; {\|XuCF#
} a>+m_]*JZ
LLoV]~dvUu
*z0Rf;
public void setSFilePath(String value) JOs kf(
{ ,wy;7T>ODd
sFilePath = value; 'Zqt~5=5
} u#Bj#y!
i+lq:St
@gQ?cU7
public String getSFileName() gADqIPu]
{ ,mz7!c9H^a
return sFileName; z80*Ylx
} x@:98P
kV3LFPf>0
;Rm';IW$
public void setSFileName(String value) p:ZQ*Ue
{ llCE}Vdh
sFileName = value; -w'g0/fD
} G/w@2lYx
c;=St1eoz
^PMA"!n8
public int getNSplitter() {96NtR0Z
{ [FBc&HN
return nSplitter; ^E%NYq_2l<
} F>E_d<m
*Tmqs@L
E;"VI2F
public void setNSplitter(int nCount) %f(4jQ0I
{ aD~S~L!
nSplitter = nCount; B =DV!oUg
} {yi!vw
} r\y\]AmF
rERtOgi
e"Z,!Q^-L
/* jT;'T$
**Utility.java v~p?YYOm<
*/ U<'$ \P
package NetFox; jASK!3pY
DvA#zX[
-ilhC Y@M
public class Utility { NCm=l
sr~VvciIy
-'i[/{
public Utility() Aiqb*v$
{ ](IOn:MuDE
9AD0|,g
nYj7r*e[
} jank<Q&w
&d"scM5
//线程睡眠 )F0Q2P1I
public static void sleep(int nSecond) T{BGg
{ paxZlA o
try{ /4+*!X
Thread.sleep(nSecond); @Z96902<t
} swhtlc@@
catch(Exception e) W5&KmA
{ 1+tPd7U
e.printStackTrace (); -1R7 8(1
} zEeix,IU
} J!'IkC$>
MOIVt) ZY
//日志 pf3-
public static void log(String sMsg) gER(&L4[
{ GU xhn
System.err.println(sMsg); 73!])!SVI
} s1T}hp
fl*49-d
L-e6^%eU
public static void log(int sMsg) ay=f1<a
{ %@;xbKj
System.err.println(sMsg); y<y9'tx
} P{8<U8E
} <XnxAA
2{L[D9c/6
I>>X-}
/* N&u(9Fxn
**TestMethod.java "%=K_WJ?
*/ XJ3aaMh"
package NetFox; "04:1J`
1sfs!b&E
~@iYP/=/Q
public class TestMethod { Uz7V2r%]
4Y@q.QP
c5{3
public TestMethod() Zg >!5{T
{ ///xx/weblogic60b2_win.exe TI3@/SB>
try{ "o<&3c4
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 8;Df/%
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); rVnolA*%
SiteFileFetch fileFetch = new SiteFileFetch(bean); $H7T|`WI.,
fileFetch.start(); bw[K^/
} "=9)|{=m
catch(Exception e){e.printStackTrace ();} *&W1|Qkg_
~"vRH
Fi#b0S
} q.p.y0
RSf*[2
})ic@ Mmd$
public static void main(String[] args) P Z+Rz1x
{ .BZ3>]F3<
new TestMethod(); $C6O<A
} 1=Q3WMT
} M{U7yE6*j*
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