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)); !QQ<Ai!E
} _yxe2[TD
for(int i=0;i<nEndPos.length-1;i++) nXM9Px!
{ 2yJ7]+Jd7Y
nEndPos = nStartPos[i+1]; dS3>q<J*a
} lk*0c{_L
nEndPos[nEndPos.length-1] = nFileLength; kKxL04
} c+E//X|
} cy&
'{j\0
4uO @`0:x
//启动子线程 4[5lX C
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ^^4K/XBve
for(int i=0;i<nStartPos.length;i++) }"&n[/8~
{ u-%r~ }
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), >tmnj/=&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), I5TQ>WJbf
nStartPos,nEndPos,i); CzzUi]*Ac{
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e-%7F]e
fileSplitterFetch.start(); @o4z3Q@
} jlRl2 #"
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), fR]p+\#8u*
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); mc0sdb,c$
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", b[{m>Fa+o#
nEndPos = " + nFileLength); (opROsFh
// fileSplitterFetch[nPos.length-1].start(); f7_\).T
3D?IG\3
c ,h.`~{
//等待子线程结束 7~!I2DV_
//int count = 0; K)Df}fVOc
//是否结束while循环 xE G+%Uk{
boolean breakWhile = false; 3t"~F%4-}
D+ah ok
VL_)]LR*)
while(!bStop) 4cXAT9
{ mC*W2#1pF
write_nPos(); i63`B+L{
Utility.sleep(500); ['51FulDR
breakWhile = true; lF;ziF
$Q`yNEc
]6a/0rg:t
for(int i=0;i<nStartPos.length;i++) l1-4n*fU
{ t/v@vJ`vSH
if(!fileSplitterFetch.bDownOver) 1zb$5{,|
{ '+)6#/*
breakWhile = false; +?URVp
break; &%|xc{i
} R7E]*:0}
} *fxep08B
if(breakWhile) T4V[RN
break; g>6:CG"
6obQ9L c
KW&nDut
//count++; KcIc'G 9
//if(count>4) (/T+Wpy?
// siteStop(); v t^r1j
} GAg.p?Sq
M?E9N{t8)a
$se !8s"
System.err.println("文件下载结束！"); S 3{Dn
} DWF >b
catch(Exception e){e.printStackTrace ();} '4J&Gpx
} Sp<hai
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tH-gaDj_
//获得文件长度 -6uH.
public long getFileSize() -0A@38, }
{ q:xtm?'$
int nFileLength = -1; *Zc9yZl2
try{ 5\uNEs$T
URL url = new URL(siteInfoBean.getSSiteURL()); }=Hf?';m
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 08`f7[JQo]
httpConnection.setRequestProperty("User-Agent","NetFox"); \U==f&G?J
ZkwJ.SuU
'g. :MQ8
int responseCode=httpConnection.getResponseCode(); UP\8w#~
if(responseCode>=400) ^/G?QR
{ Q]!6uA$A
processErrorCode(responseCode); kJ/+IGV^v
return -2; //-2 represent access is error ?(]a*~rx
} @8|~+y8,
H!p!sn
K3Huu!Tr
String sHeader; *^n^nnCwp
A3xbT\xdg
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for(int i=1;;i++) IoQr+:_R
{ C=8H)Ef,l
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); )sqaR^
//Utility.log(in.readLine()); L+_8QK<
sHeader=httpConnection.getHeaderFieldKey(i); 6KVV z/
if(sHeader!=null) QDP-E[
{ #U\$@4D
if(sHeader.equals("Content-Length")) k9cK bf@
{ bG52s
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); e,^pMg~
break; l+oDq'[q"
} 0"hiCGm'
} OO$|9`a
else yz2(_@R
break; ohtT O]\
} X!o@f$
} {K+.A 9!
catch(IOException e){e.printStackTrace ();} !TGr.R
catch(Exception e){e.printStackTrace ();} *}7U`Aa
qZ#!CPHS
c$/<l5Uw
Utility.log(nFileLength); .6LS+[
#iiwD|
ej<`CQ
return nFileLength; #T[%6(QW
} 9g96 d-
>cTjA):
ad9EG#mD#
//保存下载信息（文件指针位置） JXL'\De ;
private void write_nPos() >n(F4C-pl
{ CNq[4T'~A
try{ wBLsz/
output = new DataOutputStream(new FileOutputStream(tmpFile)); YKNb59k
output.writeInt(nStartPos.length); %Or2iuO%-,
for(int i=0;i<nStartPos.length;i++) s_TD4~ $
{ K,6OGsh
// output.writeLong(nPos); IOX:yxj
output.writeLong(fileSplitterFetch.nStartPos); EPv%LX_j
output.writeLong(fileSplitterFetch.nEndPos); Nvhy3
} ,2,W^HJ
output.close(); 6vF/e#},
} kwOeHdV^
catch(IOException e){e.printStackTrace ();} vsc&Ju%k
catch(Exception e){e.printStackTrace ();} u|T%Xy=LU
} UUGe"]V^g:
U[bgu#P;
^:+Rg}]W^
//读取保存的下载信息（文件指针位置） q#jEv-j.
private void read_nPos() $3]b>v
{ ",T`\8&@e
try{ g9`[Y~
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); k},>^qE
int nCount = input.readInt(); e+l\\9v
nStartPos = new long[nCount]; vcwK6G
nEndPos = new long[nCount]; ?3Pazc]+|
for(int i=0;i<nStartPos.length;i++) ]H>+m 9
{ J$rJd9t
nStartPos = input.readLong(); EQ/^&
nEndPos = input.readLong(); EDtCNqBS~2
} IqNpLh|[
input.close(); zWb-pF|
} JdO)YlM-
catch(IOException e){e.printStackTrace ();} #cO+<1
catch(Exception e){e.printStackTrace ();} ODek%0=
} "ee'2O
TOrMXcn!/
'g~@"9'oe
private void processErrorCode(int nErrorCode) )@_ugW-j
{ 4~*Y];!Q
System.err.println("Error Code : " + nErrorCode); ^&-a/'D$,
} `zY!`G
7=vYO|a/4
O)1E$#~
//停止文件下载 Xo8DEr
public void siteStop() bNXAU\M^
{ GkciA{
bStop = true; 7 v~ro
for(int i=0;i<nStartPos.length;i++) $WR?
fileSplitterFetch.splitterStop(); vtZ?X';wh
M/} aq
-%H%m`wD
} r6MB"4xd
} R1/q3x
//负责部分文件的抓取 J.W Ho c
**FileSplitterFetch.java ;NP[_2|-,
*/ c.0]1
package NetFox; 'in@9XO
lLMPw}r<
g|4w8ry
import java.io.*; A="fj
import java.net.*; $_FZn'Db6
`.8UKSH+
-njQc:4W,-
public class FileSplitterFetch extends Thread { :u-.T.zZl
Y"*:&E2)r
yl/a:Q
String sURL; //File URL gz4UV/qr/
long nStartPos; //File Snippet Start Position Sr"/-
long nEndPos; //File Snippet End Position <m]wi7
int nThreadID; //Thread's ID 'evv,Q{87
boolean bDownOver = false; //Downing is over *KJ7nRKx(w
boolean bStop = false; //Stop identical Hk9U&j$
FileAccessI fileAccessI = null; //File Access interface si?HkJv5
@RVOXkVo
11{y}J
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException >)3VbO
{ 8^vArS;
this.sURL = sURL; Up|f=@=
this.nStartPos = nStart; RHI&j~
this.nEndPos = nEnd; y 1nU{Sc@
nThreadID = id; 7=3O^=Q^Q
fileAccessI = new FileAccessI(sName,nStartPos);//定位 zmbZ
} .[(P
|[LE9Lq/
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public void run() 'HB~Dbq`V
{ q~O>a0f0
while(nStartPos < nEndPos && !bStop) DY.58IHg1
{ e8q4O|I_
iaRR5D-
enumK\
try{ zo44^=~%
URL url = new URL(sURL); O^NP0E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); lD3)TAW@o
httpConnection.setRequestProperty("User-Agent","NetFox"); wT/6aJoX
String sProperty = "bytes="+nStartPos+"-"; (OqHfv
httpConnection.setRequestProperty("RANGE",sProperty); G=cNzr9
Utility.log(sProperty); sOQcx\dK
5Eal1Qu
9-93aC.|}
InputStream input = httpConnection.getInputStream(); Kj!Y K~~
//logResponseHead(httpConnection); F`srE6H
GoD ?KC
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byte[] b = new byte[1024]; 0x71%=4H^x
int nRead; \JU{xQMB
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) BKZ v9
{ g ;LVECk
nStartPos += fileAccessI.write(b,0,nRead); ETm]o
//if(nThreadID == 1) f3t.T=S
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9P0yv3
} \u8,!) 4i
?l9=$'
+5-fk>o
Utility.log("Thread " + nThreadID + " is over!"); :'Xr/| s
bDownOver = true; \xeVDKJH+n
//nPos = fileAccessI.write (b,0,nRead); &57U? oY
} Pw xIz
catch(Exception e){e.printStackTrace ();} Fx5ZwT t
} LU(%K{9
} pyF5S,c
3Ta>Ki
gVA; `<
//打印回应的头信息 SB1[jcJ
public void logResponseHead(HttpURLConnection con) OHhs y|W
{ eJ:Yj ~X`<
for(int i=1;;i++) pns+y
{ G *@@K
String header=con.getHeaderFieldKey(i); piuKVU
if(header!=null) >HIt}Zh
//responseHeaders.put(header,httpConnection.getHeaderField(header)); phS>T
Utility.log(header+" : "+con.getHeaderField(header)); @?d?e+B
else pg!`SxFD
break; QPV@'.2m
} s ^3[W0hL
} ]9@X?q
Of#K:`1@
'z-D%sCA
public void splitterStop() 0 {,h.:
{ X(b1/lzA
bStop = true; fCr\u6Tb
} A!4VjE>
sbA2W~:
(Xj.iP
} pX^=be_
?$16A+
c"qPTjY
/* SXh?U,5u
**FileAccess.java kXMP=j8
*//文件访问(定位，写) Br&^09S
package NetFox; *:[b'D!A
import java.io.*; wB2}uk7
D>Ua#<52q
C rfRLsN]
public class FileAccessI implements Serializable{ -tMA
jJc07r']
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 8(^ ,r#Gy
RandomAccessFile oSavedFile; hm6pxFkX_
long nPos; 5v+L';wx[T
<uC<GDO
pkW5D
public FileAccessI() throws IOException =oPng=:
{ T(gg>_'jh
this("",0); RJLFj
} BJ2Q2WW
H<XlUCr_~+
s6IP;}
public FileAccessI(String sName,long nPos) throws IOException LC76Qi;|k
{ wM0E%6 P
oSavedFile = new RandomAccessFile(sName,"rw"); _\!0t
this.nPos = nPos; Uqr{,-]5v
oSavedFile.seek(nPos); | 4 `.#4
} "d2LyQy
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C-&#r."L
public synchronized int write(byte[] b,int nStart,int nLen) tbY SK
{ !bieo'c
int n = -1; &62`Wr0C
try{ ?N(u4atC
oSavedFile.write(b,nStart,nLen); }Py<qXH
n = nLen; jKYm/}d
} tfsh!)u?
catch(IOException e) (%.</|u
{ GgT=t)}wu
e.printStackTrace (); #c:9V2
} ~yd%~|
SK}HXG{?
B JU*`Tx
return n; +B](5z4
} `9:v*KuM#R
H RWZ0 '
'aNahzb
} `I@)<d
~T;K-9R
<nf=SRZ
/* ?!R%o
**SiteInfoBean.java v]l&dgoT
*/ G[y&`Qc)G
package NetFox; 'T6B_9GQ8
anpJAB:1
fp,1qzU[k
public class SiteInfoBean { (R,NV3m?w
sb8z_3
<XU8a:w'T
private String sSiteURL; //Site's URL c9 gz!NE
private String sFilePath; //Saved File's Path k\Yu5)
private String sFileName; //Saved File's Name ;L#LDk{Za
private int nSplitter; //Count of Splited Downloading File 3-4Nad
sj#{TTW
X}_QZO=z
public SiteInfoBean() #rqyy0k0'h
{//nSplitter的缺省值为5 ?3.(Vqwog
//default value of nSplitter is 5 2O}s*C$Xav
this("","","",5); ,?P8m"
} Xi1q]ps
L#83f]vG
4`?sE*P@`
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =d:R/Z%,
{ MoC*tImWR
sSiteURL= sURL; =1V>Vd?8.
sFilePath = sPath; WO.}DUfG+
sFileName = sName; U[K0{PbY
this.nSplitter = nSpiltter; d=Rk\F'^J
GapX$Jb,p
/1[}G!
} )Tyky%P+iI
6Cop#kW#
c,b`N0dOKL
public String getSSiteURL() 3fbD"gL
{ ,f-T1v"
return sSiteURL; CuV=C Ay>
} FFD*e-i
eG[umv.9b
'l0eo' K
public void setSSiteURL(String value) f4 Sw,A
{ b#/V;
sSiteURL = value; IPr*pQ{;c
} Z L6~Eut
7(nz<z p
\'}/&PCkr
public String getSFilePath() A~yw8v5UF
{ Q(!}t"u
return sFilePath; 8CN7+V
} .MzP}8^
*`QdkVER
Qw{\sCH>
public void setSFilePath(String value) LB64W ;#h
{ ZmR[5 mv@
sFilePath = value; R~x;X3
} R4Gg|Bh
K{r1&O>W
ba:mO$
public String getSFileName() 1o5Y9#7
{ 9$4/frd
return sFileName; an[3vKb
} ]y)R C-N
X-;Qorb^
yEw"8u'
public void setSFileName(String value) }77=<N br
{ kVG6\<c]
sFileName = value; 7}iewtdy,
} J}Z_.:JO(w
A aF5`
'#An+;x{
public int getNSplitter() |<+|Du1
{ Fh!!T%5>C
return nSplitter; wEHrer
} OV@h$fg
>Wr
n\8[G[M
public void setNSplitter(int nCount) ]9yA0,z/
{ {p lmFV
nSplitter = nCount; >I66R;
} dnWt\>6& 2
} 5 1CU@1Ie
/K<GN7vN
s2' :&5(
/* R82Zr@_
**Utility.java e5/DCz
*/ )hZ}$P1
package NetFox; j}?ZsnqV
J-%PyvK$?
'14l )1g.
public class Utility { jv#" vQ9A]
[sO<6?LY
3=L1HZH
public Utility() \z2hXT@D
{ OD@A+"
*y\tnsU
<~8f0+"
} Ud(dWj-/
JU2' ~chh
//线程睡眠 y7G|P~td
public static void sleep(int nSecond) Z a y'/b
{ _2n/vF;I+_
try{ d?qO`- ~$
Thread.sleep(nSecond); 4}YT@={g}
} C00*X[p
catch(Exception e) SD.*G'N&2f
{ `3s-%>
e.printStackTrace (); 1bAp{u&
} p{#7\+}
} F-OZIo
3&d+U)E
//日志 KUn5S&eB
public static void log(String sMsg) @3=<wz<
{ }8KL]11b
System.err.println(sMsg); a}]@o"
} (#Kvm
rTiuQdvo
Oes+na'^
public static void log(int sMsg) u=i^F|
{ lxJ.h&"P
System.err.println(sMsg); }pZnWK+
} .Zz7LG{
} 5DBd [u3
uUB%I 8
L}pFb@
/* I8>1RXz
**TestMethod.java PvCE}bY{}
*/ 1pr_d"#4
package NetFox; ;rdLYmmx^
6$;)CO!h
bg. KkJMrR
public class TestMethod { qUg4-Z4
7lOiFw
C&"2`ll
public TestMethod() w~-d4MNM
{ ///xx/weblogic60b2_win.exe 6$.Xj\zl
try{ O|m-k0n
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); p=T\3_q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); @_nhA/rlc
SiteFileFetch fileFetch = new SiteFileFetch(bean); WSwmX3rn
fileFetch.start(); |0%UM}
} Om~C0
catch(Exception e){e.printStackTrace ();} A84HaRlkF5
]TOY_K8"z#
a5&j=3)|
} E6)mBAE
Sw)ftC~d
(#Aq*2Z.
public static void main(String[] args) DF =.G1
{ FX 3[U+
new TestMethod(); K;lC#
} =@MKU
} ]x\wP7x
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