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)); w7?fJ")
} $C\ETQ@
for(int i=0;i<nEndPos.length-1;i++) P+hcj p*
{ ~/`/r%1/J
nEndPos = nStartPos[i+1]; &su'znLV
} TSP%5v;Dh
nEndPos[nEndPos.length-1] = nFileLength; 0Xh_.PF
} Xh;.T=/E|
} VjM3M<!g>M
hHE~/U
h.>SVQzU
//启动子线程 E:pk'G0bZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; :9UgERjra
for(int i=0;i<nStartPos.length;i++) J/4T=:\
{ %Gh5!e:$SI
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6*9wGLE
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), R}=5:)%w
nStartPos,nEndPos,i); ?ZRF]\dP]
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8~o']B;lJ
fileSplitterFetch.start(); :'Qiwf&
} `sYFQ+D#O
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), M@A3+v%K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); aDNB~CwZZ
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ls 5iE
nEndPos = " + nFileLength); uPz+*4+
// fileSplitterFetch[nPos.length-1].start(); U8Y%rFh1
Q[j| 2U
!RmVb}m
//等待子线程结束 j HHWq>=d
//int count = 0; ]u_j6y!
//是否结束while循环 rY_~(?XS
boolean breakWhile = false; 9Lb96K?=>
nTqU~'d'
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while(!bStop) [b3!H{b#
{ QF"7.~~2
write_nPos(); V^2_]VFj
Utility.sleep(500); =#G 2}8mQD
breakWhile = true; N*-tBz
{q0+PzgP
u<BU4c/p
for(int i=0;i<nStartPos.length;i++) -&8( MT*
{ &R72$H9C8i
if(!fileSplitterFetch.bDownOver) S:_Ms{S
{ YO7U}6wBt
breakWhile = false; Lj1l]OD
break; ;?2)[a
} hC:'L9Y
} 4qOzjEQ
if(breakWhile) ~$HB}/
break; Y_'ERqQ
n N<N~
t/iI!}
//count++; b&z#ZY
//if(count>4) lYx_8x2
// siteStop(); Zo3!Hs ZA
} ;l@94)@0
uks75W!}U
h:%,>I%{
System.err.println("文件下载结束！"); d/7fJ8y8
} MgJ6{xzz
catch(Exception e){e.printStackTrace ();} cfLF@LW!])
} aDbqh~7
S>yiD`v
r6m^~Wq!}
//获得文件长度 }e[ E
public long getFileSize() ?,vLRq.
{ JmI%7bH@
int nFileLength = -1; OsgPNy0
try{ !Z!)$3bB
URL url = new URL(siteInfoBean.getSSiteURL()); *d1BpR%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); kt6x"'"1
httpConnection.setRequestProperty("User-Agent","NetFox"); rQjk
]at$ohS
(g##wa)L
int responseCode=httpConnection.getResponseCode(); a1cX+{W
if(responseCode>=400) |`T(:ZKXZ2
{ 7>Z|K
processErrorCode(responseCode); ')uYI;h9
return -2; //-2 represent access is error &`D$w?beg
} U zy@\
MKHnA|uQ](
\<LCp;- K
String sHeader; w$}q`k'
#t+?eye~
:5t4KcQ
for(int i=1;;i++) -/Q5?0z
{ pHeG{<^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); F5o8@ Ib]:
//Utility.log(in.readLine()); =L!&Z
sHeader=httpConnection.getHeaderFieldKey(i); :R;w<Tbz"
if(sHeader!=null) s6`E.Eevm
{ P3zUaN\c
if(sHeader.equals("Content-Length")) RM2Ik_IH[l
{ ewMVUq*:
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); F]$ Nu
break; 37U8<
} ]>n{~4a
} @ st>#]i4
else [?]N GTr#
break; 7H7 Xbi@
} 6$`<Y?
} [EAOk=X
catch(IOException e){e.printStackTrace ();} 0,Ds1y^
catch(Exception e){e.printStackTrace ();} bfxE}>
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MP%#)O6
Utility.log(nFileLength); xIM,0xM2
3q]0gU&??
/vQ)$;xf#
return nFileLength; V}E['fzBFV
} !nmZ"n|}p
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<y6`8J7:
//保存下载信息（文件指针位置） PQHztS"
private void write_nPos() -)V0D,r$[
{ ,1-%C)
try{ Y+-yIMt$r
output = new DataOutputStream(new FileOutputStream(tmpFile)); o|xf2k
output.writeInt(nStartPos.length); S^QEctXU
for(int i=0;i<nStartPos.length;i++) q\fbrv%I4
{ !sT>]e
// output.writeLong(nPos); K9<8FSn
output.writeLong(fileSplitterFetch.nStartPos); a5a ;Fp
output.writeLong(fileSplitterFetch.nEndPos); r:QLU]
} ti5fsc
output.close(); aBAoSn
} %'2P4(
catch(IOException e){e.printStackTrace ();} P;5)Net1X
catch(Exception e){e.printStackTrace ();} }z]d]
} UF9={fN1
Ac_P^
-laH^<jm5
//读取保存的下载信息（文件指针位置） HhbBt'fH
private void read_nPos() |_53So:g
{ )~'UJPK
try{ uLdHE5vr
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5wK==hZ
int nCount = input.readInt(); vl (``5{
nStartPos = new long[nCount]; 1g;2e##)
nEndPos = new long[nCount]; }8O9WS
for(int i=0;i<nStartPos.length;i++) }&v}S6T
{ L$ T2 bul
nStartPos = input.readLong(); "aGmv9\
nEndPos = input.readLong(); rZUTBLZ`j
} &9e
input.close(); 4 ]oe`yx
} x?i wtZ@
catch(IOException e){e.printStackTrace ();} jFQy[k-B
catch(Exception e){e.printStackTrace ();} !'$*Z(
} )<x9t@$
M"z=114
0:{W t
private void processErrorCode(int nErrorCode) Bc=(1ty)
{ M+t)#O4
System.err.println("Error Code : " + nErrorCode); xU;SRB
} l+;S$evY
<"Y>|X
B>u`%Ry&
//停止文件下载 8@3=SO
public void siteStop() >?+Rtg|${
{ i4YskhT
bStop = true; h7]+#U]mi
for(int i=0;i<nStartPos.length;i++) }s2CND
fileSplitterFetch.splitterStop(); :(q4y-o6
W6?=9].gc
J.iz%8
} N XB8u6
} Uw4iWcC
//负责部分文件的抓取 BA a:!p
**FileSplitterFetch.java u>fs yn9c
*/ 6*,55,y
package NetFox; 4K cEJlK5
F=F84_+K
shw?_#?1dy
import java.io.*; ^!tX+`,6^
import java.net.*; T"\d,ug5[
N[@~q~v
*)[fGxz \
public class FileSplitterFetch extends Thread { Od.@G~
+}jzge"
/`cy4<
String sURL; //File URL DN^+"_:TB
long nStartPos; //File Snippet Start Position =p|IWn{P
long nEndPos; //File Snippet End Position 3[#^$_96b
int nThreadID; //Thread's ID PTHxvml
boolean bDownOver = false; //Downing is over cc${[yj)
boolean bStop = false; //Stop identical s}JifY`
FileAccessI fileAccessI = null; //File Access interface 'v'[_(pq
6$"IeBRO
u?>},M/
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException s:{[Y7\?
{ 9DBX.|
this.sURL = sURL; >V.?XZ nt
this.nStartPos = nStart; %:C6\4
this.nEndPos = nEnd; a;$V;3C{b&
nThreadID = id; lLQcyi0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 tDETRjTA
} @<DRFP
:%sG'_d
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public void run() @+;.W>^h
{ #~Xj=M%
while(nStartPos < nEndPos && !bStop) ]Mq-67
{ H[w';u[%
dpz@T>MS=
FqyxvL.
try{ ,{IDf
URL url = new URL(sURL); (bm> )U=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Dp['U
httpConnection.setRequestProperty("User-Agent","NetFox"); Pjq'c+4.yL
String sProperty = "bytes="+nStartPos+"-"; 9ad`q+kY
httpConnection.setRequestProperty("RANGE",sProperty); R1JD{
Utility.log(sProperty); xS,F DPA
}^I36$\
T Tbe{nb
InputStream input = httpConnection.getInputStream(); @Mg&T$
//logResponseHead(httpConnection); 54{E&QvL8o
UR'v;V&Cb\
;(mNjxA
byte[] b = new byte[1024]; *v#V%_o
int nRead; RAa1^Qb
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) -75mgOj.#
{ <Hv/1:k}
nStartPos += fileAccessI.write(b,0,nRead); b\^DQZmth
//if(nThreadID == 1) RH,x);J|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tIn`L6b
} CeU=A9
v$\<L|
m p_7$#{l
Utility.log("Thread " + nThreadID + " is over!"); a2?@OJ
bDownOver = true; ;u`8pF!_eE
//nPos = fileAccessI.write (b,0,nRead); !,$K;L
} Bor_(eL^
catch(Exception e){e.printStackTrace ();} RaLV@>jPm
} zw'%n+5m
} V+D<626o
it{Jd\/hR
{'alA
//打印回应的头信息 ftmPdha%+
public void logResponseHead(HttpURLConnection con) nh7_ jEX
{ UvMkL
for(int i=1;;i++) _zbIS&4
{ ,J2qLH1
String header=con.getHeaderFieldKey(i); Q~.t8g/
if(header!=null) ~(*tcs]hY
//responseHeaders.put(header,httpConnection.getHeaderField(header)); x+~!M:fAc9
Utility.log(header+" : "+con.getHeaderField(header)); P,zQl;
else \v+>qY<q
break; T!?tyW
} XR VZU~ZV
} ?(zCv9Pg
AP z"k?D0
tvno3"
public void splitterStop() v?8i;[
{ PcbhylKd
bStop = true; +*Wlj8
} jD<xpD
6 o
W.s8!KH:
} F6J]T6Y
.[eC w
l(x0d
/* Zs|Ga,T
**FileAccess.java ]Vj($O:
*//文件访问(定位，写) @=z.^I30
package NetFox; wIAH,3!
import java.io.*; Fa`%MR1
Tei2[siA5
yQ^,>eh
public class FileAccessI implements Serializable{ QiA}0q3]0
H9'psv
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 c?<)!9:
RandomAccessFile oSavedFile; tKyGD|g S
long nPos; s[eSPSFZ
ho6hjhS|u
QSzht$8
public FileAccessI() throws IOException 3st?6?7|
{ A*:|d~
this("",0); ,gpEXUp\
} 3H<%\SYp
C(h<s e?
m<#^c?u
public FileAccessI(String sName,long nPos) throws IOException atd;)o0*0
{ ,j{tGj_
oSavedFile = new RandomAccessFile(sName,"rw"); ]7TOA$Q
this.nPos = nPos; UsA fZg8
oSavedFile.seek(nPos); E,ilJl\
} 5|jY
a0k;way
]iW:YNvXA
public synchronized int write(byte[] b,int nStart,int nLen) QoUdTIIL
{ ^B%ki
int n = -1; 'y>Y*/
try{ y:Gn58\o
oSavedFile.write(b,nStart,nLen); ?Hdu=+ZV
n = nLen; ) x+edYw
} n(V{ [
catch(IOException e) aso8,mpZuA
{ nVoWER:
e.printStackTrace (); _pb*kJ
} %MGt3)
2[=3-1c
7l/ZRz}1
return n; p<\!{5:
} &N=vs
QEut@L
NCT:!&
} hP'4PLK
yFeFI@Hp 3
{7DXSe4
/* a-S tOO5s
**SiteInfoBean.java IIT[^_g
*/ 6`6 / 2C$%
package NetFox; NNr6~m)3v
\}4*}Lr
\`z%5/@f;
public class SiteInfoBean { 9MO=f^f-
S,5>/'fy0
.9Cy<z
private String sSiteURL; //Site's URL fwA8=oSZd
private String sFilePath; //Saved File's Path L58#ri=
private String sFileName; //Saved File's Name lw~ V
private int nSplitter; //Count of Splited Downloading File Xm|~1 k_3
){)-}M
=Yl ea,S
public SiteInfoBean() dR_6j}
{//nSplitter的缺省值为5 (_@]-
//default value of nSplitter is 5 -l_B;Sb:e
this("","","",5); PW5)") z
} Iw.!*0$
|cnps$fk~
9.xRDk
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) #C.
{ #Ff8_xhP2
sSiteURL= sURL; }wp/,\_ >
sFilePath = sPath; }ssja,;
sFileName = sName; }6.@
this.nSplitter = nSpiltter; Ua:@,};
}.'rhR+
2ry@<88
} 4'`P+p"A
0fvOA*UP
S2\;\?]^~
public String getSSiteURL() ORF:~5[YS`
{ +ansN~3
return sSiteURL; =+mb@#="m
} uJH[C>
\X\f~CB
| ?vm.zp
public void setSSiteURL(String value) eC%Skw
{ Cy/VH"G=
sSiteURL = value; eCsk\f`
} U+>M@!=
_4)z:?G5
&wY$G! P
public String getSFilePath() RjvW*'2G
{ =9 )k:S(
return sFilePath; ZQfPDH=
} y9d"sqyh
`#l3a
(57!{[J
public void setSFilePath(String value) o<3$|`S&
{ j-R*!i
sFilePath = value; y2jw3R
} 3TCRCz
Ic_NQ<8
>l AtfN='
public String getSFileName() 6(-s@{
{ of_y<dd[G
return sFileName; KgkRs?'z
} sfr+W-7kx
M+VWAh#uD
>L!c} Ku
public void setSFileName(String value) _9 '_w&
{ v ;}s`P\"
sFileName = value; EZ|v,1`e
} 4LB8p7$|a3
^5Lk}<utw
n6WKk+
public int getNSplitter() 8aWEl%
{ h ':ZF
return nSplitter; EmcLW74
} !YjxCx
7CuZ7!>$
}kr?+)wB
public void setNSplitter(int nCount) ;XawEG7" U
{ EI 35&7(
nSplitter = nCount; V+lF|CZb5
} xIa7F$R 0
} UWKgf? _
Rb0I7~Z%'d
0]
/* PgK7CG7G
**Utility.java y-bUVw!Y
*/ ?hkOL$v<9}
package NetFox; n8F5z|/
/o m++DxV
RhHm[aN
public class Utility { U3V5Jor#
1s.2z[B~
|SjRss:i+
public Utility() ;mk[!
{ )'U0n`=
A/'po_'uy
]1<GZ`
} 9/(jY$Ar
3)W zX
//线程睡眠 ^r&)@R$V
public static void sleep(int nSecond) mvZ#FF1,J
{ s<FBr,
try{ }Rw,4
Thread.sleep(nSecond); .M^[/!
} I!S Eb
catch(Exception e) !>`Fg>uy
{ JaRsm'SIk~
e.printStackTrace (); R03 Te gwA
} DaQl ip
} R);Hd1G
qy3@> 1G
//日志 rtj`FH??11
public static void log(String sMsg) \]u;NbC]
{ (*9.GyK
System.err.println(sMsg); rR#Ditn^
} VWE>w|'
;[Mvk6^'R
9KXL6#h
public static void log(int sMsg) 8XB[CbO
{ ^'V :T Y
System.err.println(sMsg); rKrHd
} f 5v&4
} ?@.v*'qR
Jo\P,-\(
h<Aq|*
/* ai/|qYf
**TestMethod.java _?I{>:!|
*/ (jc& Fk
package NetFox; cgMF?;V
sF{aG6u
X@\W* nq
public class TestMethod { DpT9"?g7
g|>LT_
sCFxn
public TestMethod() kUf i
{ ///xx/weblogic60b2_win.exe (aa2uctTn
try{ {rUg,y{v
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); @x}"aJgl
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); kyJbV[o<#
SiteFileFetch fileFetch = new SiteFileFetch(bean); "Wwu Ty|
fileFetch.start(); p%3z*2,(
} !ajBZ>Q
catch(Exception e){e.printStackTrace ();} `5IrV&a
|vI`u[P
?;ok9Y
} G.rz6o;
<e2l@@#oy
lvO6&sF1
public static void main(String[] args) e7RgA1
{ K*>%,mP$i
new TestMethod(); VVas>/0qr
} 5qb93E"C
} 4E39]vb
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