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)); _V7s#_p
} Vl&?U
for(int i=0;i<nEndPos.length-1;i++) TJK[ev};S
{ *Q?tl\E
nEndPos = nStartPos[i+1]; #49kjv@
} g?z/2zKR
nEndPos[nEndPos.length-1] = nFileLength; 1v.c 6~
} Rwz0poG`WG
} )u[emv$
A kC1z73<
$4h5rC g0
//启动子线程 ywGd>@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; PQ5QA61
for(int i=0;i<nStartPos.length;i++) }dgfqq
{ 4T|b Cs?e
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Oo5w?+t
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), `6~Aoe
nStartPos,nEndPos,i); "s0)rqf<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 2$+bJJM
fileSplitterFetch.start(); cW@Zd5&0S
} +ElfZ4
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hT`J1nNt
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); K|zZS%?$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 6jE|
nEndPos = " + nFileLength); &Sw%<N*r
// fileSplitterFetch[nPos.length-1].start(); u0|8Tgf
IzikDc10
)dbB=OZ
//等待子线程结束 a{^m-fSaR"
//int count = 0; gQWa24
//是否结束while循环 0D\#Pq v
boolean breakWhile = false; }X)&zenz
,':fu
e:fy#,HEj{
while(!bStop) xS4w5i2
{ 8m2Tk\;:
write_nPos(); n.!#P|
Utility.sleep(500); ZSjMH .Ij"
breakWhile = true; yu!h<nfzA
b=yx7v"r
A9I{2qW9+Z
for(int i=0;i<nStartPos.length;i++) uki#/GzaO
{ +ga k#M"n\
if(!fileSplitterFetch.bDownOver) HHDl8lo
{ DFZkh^PFd
breakWhile = false; T!+5[
break; QM5R`i{r
} ;RDh~EV
} y"bByd|6
if(breakWhile) k1w_[w[
break; 6& e3Nt
i2E)P x
>7lx=T x
//count++; 60P#,o@G
//if(count>4) `q}I"iS
// siteStop(); zMbN;tu
} i UCXAWP
7Ri46Tkt
Xe6w|
System.err.println("文件下载结束！"); ;X?}x%$
} 1O/+8yw
catch(Exception e){e.printStackTrace ();} R;s?$;I
} &]"
")O%86_Q:
7X0Lq}G@
//获得文件长度 %HGD;_bhI
public long getFileSize() U 9_9l7&r
{ (D#B_`;-
int nFileLength = -1; Oft-w)cYz,
try{ ii[F]sR\
URL url = new URL(siteInfoBean.getSSiteURL()); qkt0**\
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); d4u})
httpConnection.setRequestProperty("User-Agent","NetFox"); t2/#&J]
6IBgt!=,
#pP[xE"Y
int responseCode=httpConnection.getResponseCode(); R)_%i<nq\
if(responseCode>=400) fol,xMc&
{ PmkR3<=leg
processErrorCode(responseCode); \Jx04[=
return -2; //-2 represent access is error KK&rb~
} "'c A2~
f,h J~
h].<t&
String sHeader; "$#xK|t
;YA(|h<
Dd'm U
for(int i=1;;i++) >.Chl$)<
{ E(O74/2c8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ykl .1(
//Utility.log(in.readLine()); rSZd!OQ
sHeader=httpConnection.getHeaderFieldKey(i); 3.|S
if(sHeader!=null) .<jr0,i
{ }Mstjm
if(sHeader.equals("Content-Length")) }#L^!\V}
{ *@Lp`thq
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); iP =V8g?L
break; d74d/l1*{
} 2)G %)'
} 9!6f-K
else j/R[<47
break; Ja,wfRq
} KC/=TSSXd.
} -m)X]]~C
catch(IOException e){e.printStackTrace ();} r[2ILe
catch(Exception e){e.printStackTrace ();} }Ga\wV
gRCdY8GH
CnpV:>V=
Utility.log(nFileLength); *!q1Kr6r
C`$n[kCJ
#r#1JtT
return nFileLength; T=iJGRctB
} Id_2PkIN$~
r"C
#bUXgn>
//保存下载信息（文件指针位置） YM1'L\^
private void write_nPos() 3vuivU.3
{ p2ogn}`
try{ LCZ\4g05
output = new DataOutputStream(new FileOutputStream(tmpFile)); &|Bc7+/P
output.writeInt(nStartPos.length); _y),J'W^3u
for(int i=0;i<nStartPos.length;i++) tz5e"+Tz
{ W=j[V Oq
// output.writeLong(nPos); k`So -e-
output.writeLong(fileSplitterFetch.nStartPos); CLRiJ*U
output.writeLong(fileSplitterFetch.nEndPos); ZIf
} 48:>NW
output.close(); wLi4G@jJ
} +fC=UAZ
catch(IOException e){e.printStackTrace ();} @LS@cCC,a
catch(Exception e){e.printStackTrace ();} rX4j*u2u
} kW*f.!
tQ8.f
dYG,_ji
//读取保存的下载信息（文件指针位置） v'U{/ ,x
private void read_nPos() y`\@N"Cf
{ fa++MNf}3
try{ :Pvzl1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gYNjzew'
int nCount = input.readInt(); 1$D_6U:H0
nStartPos = new long[nCount]; 9`1O"R/
nEndPos = new long[nCount]; .LZwuJ^;
for(int i=0;i<nStartPos.length;i++) ).Fpgxs
{ @aAW*D~-J
nStartPos = input.readLong(); |%J{RA
nEndPos = input.readLong(); -7*ET3NSI/
} 4[;X{ !
input.close(); F<L EQ7T
} :e_V7t)o
catch(IOException e){e.printStackTrace ();} V,mw[Hw
catch(Exception e){e.printStackTrace ();} }j^i}^Du,
} N9jH\0nG
kddZZA3`
7Nk!1s:
private void processErrorCode(int nErrorCode) ]ro*G"-_1#
{ '_GrD>P)-
System.err.println("Error Code : " + nErrorCode); xfpa]Z
} Jbjmv:db
j<Bkj/
)we}6sE"
//停止文件下载 6%t1bM a
public void siteStop() o<[#0T^K
{ |_] Q$q[[%
bStop = true; 8kU!8^mH
for(int i=0;i<nStartPos.length;i++) C"!gZ8*\!9
fileSplitterFetch.splitterStop(); M@`;JjtSA
pk^K:Xs}
CS@FYO
} T?x[C4wf+
} 8dO!
//负责部分文件的抓取 &7`^i.fh)
**FileSplitterFetch.java YpH&<$x:
*/ SSPHhAeH8
package NetFox; A Y*e@nk\
UaWl6 Y&Vu
XiL~TCkx4
import java.io.*; |2RC#]/-Y
import java.net.*; j7jCm:
;%<,IdhN
X;i~<Tq
public class FileSplitterFetch extends Thread { {)BTR%t
g'H$R~ag
`+o2DA)#(
String sURL; //File URL )Qe~8u@?
long nStartPos; //File Snippet Start Position ;nodjbr,j
long nEndPos; //File Snippet End Position tKuVQH~D
int nThreadID; //Thread's ID ToJ$A`_!`
boolean bDownOver = false; //Downing is over z.kvX+7'
boolean bStop = false; //Stop identical (BTVD,G
FileAccessI fileAccessI = null; //File Access interface Y&S24aql
#:[t^}
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException bmfI~8
{ ' 0J1vG~c
this.sURL = sURL; g]4(g<:O
this.nStartPos = nStart; vhpNpgz
this.nEndPos = nEnd; Kla'lCZ
nThreadID = id; $6mX
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ~io szX
} 43mP]*=A
te3}d'9&|
.!f$ \1l
public void run() (-ufBYO6
{ MUTj-1H6)
while(nStartPos < nEndPos && !bStop) iPd[l{85Z
{ *h'=3w:G
g;2?F[8Th
-o!$tI&
try{ N'^&\@)xiU
URL url = new URL(sURL); M}yDXJx
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); U.DDaT1
httpConnection.setRequestProperty("User-Agent","NetFox"); M%ICdIc'
String sProperty = "bytes="+nStartPos+"-"; ` :o4'CG
httpConnection.setRequestProperty("RANGE",sProperty); 77\]B
Utility.log(sProperty); 8,C*4y~
y~q8pH1
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InputStream input = httpConnection.getInputStream(); 0`X]o'RxS
//logResponseHead(httpConnection); $,,op(
P*FMwrJj>r
IF44F3(V4
byte[] b = new byte[1024]; syaPpM Q-
int nRead; lfqiyYFm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) t m7^yn:
{ 9~p[
nStartPos += fileAccessI.write(b,0,nRead); c(!6^qk]!`
//if(nThreadID == 1) ]ooIrY8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !HnXXVW
} nQ5n-A&["
A-ZN F4
7UdM
Utility.log("Thread " + nThreadID + " is over!"); U<DZ:ds?T
bDownOver = true; Cj{1H([-
//nPos = fileAccessI.write (b,0,nRead); }+C2I
} H@%GSE
catch(Exception e){e.printStackTrace ();} Uk^B"y_
} wVEm:/;z&
} AaWs}M
ioYGZ%RG#
[_1G@S6Ex
//打印回应的头信息 PE5R7)~A
public void logResponseHead(HttpURLConnection con) +RyjF~[e
{ VXR>]HUF
for(int i=1;;i++) v^d]~!h
{ CF?1R
String header=con.getHeaderFieldKey(i); (O.d>
if(header!=null) C~o7X^[R\
//responseHeaders.put(header,httpConnection.getHeaderField(header)); j)<IRD^
Utility.log(header+" : "+con.getHeaderField(header)); >zXsNeGQR
else &6ZD136
break; e[&L9U6GW-
} q,93nhs "
} *X+79vG:
}a/x._[s
J&.{7YF
public void splitterStop() L.S;J[a;
{ " @v <Bk
bStop = true; p<,*3huj
} M$/|)U'W
1*9U1\z
}]lr>"~y}
} L"o>wYx
gm igsXQ
Z -W(l<
/* >[*8I\*@n
**FileAccess.java {L/tst#C
*//文件访问(定位，写) 05b_)&4R
package NetFox; A v2 08}Y
import java.io.*; "1L$|
G(p`1~xm
{ g/0x,-Z
public class FileAccessI implements Serializable{ _kU:Z
}:us:%
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 ]yK7PH-{L
RandomAccessFile oSavedFile; BG6B:
long nPos; OY;*zk
Gd-'Z_b
<<+\X:,
public FileAccessI() throws IOException G Uon/G8
{ [AYOYENp-
this("",0); k1{K*O$e
} wt!nMQ
VF?<{F
[RLN;(0n
public FileAccessI(String sName,long nPos) throws IOException =5/9%P8j9
{ 8<8:+M}
oSavedFile = new RandomAccessFile(sName,"rw"); pTPi@SBaP{
this.nPos = nPos; mH%yGBp_
oSavedFile.seek(nPos); !F A]
} x:),P-~w
m1B+31'>^
b:lP%|7
public synchronized int write(byte[] b,int nStart,int nLen) jL%x7?*U0
{ 8Kg n"M3
int n = -1; j|U#)v/
try{ 8ZM&(Lz7u
oSavedFile.write(b,nStart,nLen); *K|W /'_&
n = nLen; pA9+Cr!0Q
} eg(6^:z?f
catch(IOException e) eJxw)zd7
{ qf!p 9@4F[
e.printStackTrace (); YH vLGc%
} oU056
g!lWu[d
$Tu61zq
return n; iV'k}rXC
} N/%WsQp
pGJ>O/%
uE%r/:!k4$
} ([SU:F!uW(
}001K
bCo7*<I4
/* fZ0M%f
**SiteInfoBean.java =G7m)!
*/ cq}EZ@ .
package NetFox; `Aw^H!
. $BUw
=Je[c,&j$?
public class SiteInfoBean { tnH2sHby
$*e2YQdLo
B* ?]H*K
private String sSiteURL; //Site's URL DJ'zz&K
private String sFilePath; //Saved File's Path coW:DFX
private String sFileName; //Saved File's Name JMrEFk
private int nSplitter; //Count of Splited Downloading File SxOC1+Oy
N5Q[nd
c3jx+Q
public SiteInfoBean() ,\_1w
{//nSplitter的缺省值为5 ,K9*%rW)
//default value of nSplitter is 5 WI-&x '
this("","","",5); % tS,}ze
} /t+f{VX$
O(fM?4w
7gf05Z'=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) hQYL`Dni
{ RL!Oi|8
sSiteURL= sURL; 9s\A\$("l
sFilePath = sPath; }>>1<P<8-
sFileName = sName; #|L8tuWW
this.nSplitter = nSpiltter; +R3k-' >
39:bzUIF
?9e_gV{&;
} O_`VV*
}Yb[
^E;kgED5
public String getSSiteURL() U#lCj0iUt,
{ A P)L:7w'e
return sSiteURL; Bt@^+vH ~
} Q# ~Q=T'<
_K]_ @Ivh
|2O]R s
public void setSSiteURL(String value) 24 [+pu
{ f(/lLgI(
sSiteURL = value; 6 Q%jA7
} 8IlunJ
Gr*r=s
6wBx;y |
public String getSFilePath() QoI3>Oj=
{ W0dSsjNio
return sFilePath; th
} ?qPo=~y01
SheM|I~de
.B7,j%1r
public void setSFilePath(String value) \H1(PA
{ u_@f$
sFilePath = value; !hJ+Lp_
} 5eLtCsHz
q ?|,O;?
|cK*~
public String getSFileName() vx>b^tJKC
{ 94h]~GqNi
return sFileName; \:b3~%Fz
} >")Tf6zw&
z>LUH
/Lfm&;
public void setSFileName(String value) kjIAep0rT
{ ^yWL,$
sFileName = value; gZN8!#h}B
} 9B{k , 1
i+A3~w5c
~-ia+A6GIV
public int getNSplitter() ]^yFaTfS
{ 8[a=OP
return nSplitter; <^VJy5>
} [)H&'5 +F
bGN:=Y'
6Y^23W F
public void setNSplitter(int nCount) nr95YSH
{ ,c;Kzp>e
nSplitter = nCount; H3z:ZTI
} {x|[p_?
} 8m-U){r!U^
\HqNAE2T
t)~"4]{*}D
/* @@R7p
**Utility.java Pr3qo4t.L
*/ {+][5<q
package NetFox; <`.X$r*
o)h_H;
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public class Utility { m,VOx7%n
{&cJDqz5=
|z9*GY6RU
public Utility() p, h9D_
{ E%yNa]\P
%aHB"vi6
2y//'3[
} SON-Z"v
+NeOSQSj
//线程睡眠 rA3$3GLQ-
public static void sleep(int nSecond) Jb0`42
{ tRs [ YK
try{ p)jk>j B
Thread.sleep(nSecond); rV2WnAb[H&
} -z-C*%~
catch(Exception e) *F+KqZ.2
{ g,Lq)'N;O
e.printStackTrace (); P2NQHX
} ^|/TC!v]M
} ]3x?
\9cbI3rGz
//日志 HguT"%iv
public static void log(String sMsg) _>5(iDW0
{ Vp#JS3Y
System.err.println(sMsg); E-4b[xNj*+
} 6hw=
|ax3sAg
sGi"rg#
public static void log(int sMsg) S ^"y4-2
{ )SaGH3~*C
System.err.println(sMsg); ?ME6+Z\
} [glLre^
} 9%k2'iV7
zpzK>DH(
Cl5uS%g
/* zvvhFN2s
**TestMethod.java $ZUdT
*/ 18|m)(W
package NetFox; '<jyw
u#Pa7_zBj]
srr :!5
public class TestMethod { |v`AA?@{8
}K7#Q
GD&uQ`Y5
public TestMethod() .!Qki@
{ ///xx/weblogic60b2_win.exe (iBNZ7sJ
try{ aEFJ;n7m
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); `EEL1[:BR
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); c#XXp"7k2
SiteFileFetch fileFetch = new SiteFileFetch(bean); FTH|9OP
fileFetch.start(); 1A?W:'N
} mf A{3
catch(Exception e){e.printStackTrace ();} tGD6AI1"I
i{Uc6R6
&Q%zl9g(g
} qt"G[9;
+@A
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public static void main(String[] args) ^T( .k=
{ T%x}Y#U'`
new TestMethod(); |Z|-q"Rf
} |+"<wEKI
} 10G}{
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