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)); LZM,QQ
} \T`["<
for(int i=0;i<nEndPos.length-1;i++) .73zik
{ aUW/1nQHa
nEndPos = nStartPos[i+1]; G[3k
} 6x_T@
nEndPos[nEndPos.length-1] = nFileLength; 8M^wuRn
} L6:W'u^
} F&QTL-pQW
3ar=1_Ar
aqs%m (
//启动子线程 J]}FC{CD!
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; >*dQqJI
for(int i=0;i<nStartPos.length;i++) kDzj%sm!
{ *me,(C
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), xMDrE?
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *O@sh
nStartPos,nEndPos,i); 4E=0qbt8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); \Z)#lF|^
fileSplitterFetch.start(); a`H\-G
} FUaI2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +7Yu^&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); hCzjC|EO~
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", #(%t*"IY;
nEndPos = " + nFileLength); )n7|?@5U
// fileSplitterFetch[nPos.length-1].start(); l80bHp=
8p (!]^z
fokwW}>B[f
//等待子线程结束 fyI_
//int count = 0; D@8jGcz62
//是否结束while循环 b'velj3A
boolean breakWhile = false; RT%x&j
V: ^JC>6
aje^Z=]
while(!bStop) ;rd6ko
{ \bhOPK>w
write_nPos(); 9~@<-6jE3b
Utility.sleep(500); J &!B|TS
breakWhile = true; S|"Fgoj r
+}Xr1fr{jw
(/"thv5vT{
for(int i=0;i<nStartPos.length;i++) Bvz62?
{ Wk@ eV\H71
if(!fileSplitterFetch.bDownOver) BlXX:aZv
{ /7bw: h;
breakWhile = false; NQ?x8h3
break; n0_B(997*
} 4d!S#zx
} Nd`HB=ShJ
if(breakWhile) R0%?:! F
break; xE%O:a?S
OI+E (nA
n`]l^qE
//count++; 3&es]1b
//if(count>4) }wG,BB%N
// siteStop(); wGPotPdE2
} EMLx?JnP
osl=[pm
mA&=q_gS
System.err.println("文件下载结束！"); W.^Ei\w/t
} Cz_AJ-WR
catch(Exception e){e.printStackTrace ();} /Zc#j^_
} 2s 7mI'
e1Ob!N-
MRQZIi
//获得文件长度 !g8*r"[UJ
public long getFileSize() \M9h&I\7
{ [*Q-nZ/L
int nFileLength = -1; ! ,@ZQS
try{ Zvxp%dES
URL url = new URL(siteInfoBean.getSSiteURL()); pA<eTlH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); t\8&*(&3F
httpConnection.setRequestProperty("User-Agent","NetFox"); C1d 04Q
@rF/]UJ
MEEAQd<*
int responseCode=httpConnection.getResponseCode(); RcQ>eZHl
if(responseCode>=400) G+U3wF],
{ ~;[&K%n
processErrorCode(responseCode); R2l[Q){!
return -2; //-2 represent access is error rJDnuR
} [[w2p
eK'wVg#
(^LS']ybc
String sHeader; \^LWCp,C"
+semfZ)
rj3YTu`
for(int i=1;;i++) 4.8nY\_WF
{ {7qA&c=
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); >8|+%pK8<
//Utility.log(in.readLine()); `fz,Lh*v
sHeader=httpConnection.getHeaderFieldKey(i); =`-|&
if(sHeader!=null) =+<d1W`>0
{ u,eZ6
if(sHeader.equals("Content-Length")) #4><r.v3
{ V5AW&kfd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); \^&
break; ;UrK{>B
} ;|<(9u`
} ~Q?!W0ZBE
else Lj8)'[K"
break; n+HsQ]z.
} 3y ryeS
} X8b|]Nr
catch(IOException e){e.printStackTrace ();} [SkKz>rC
catch(Exception e){e.printStackTrace ();} qgx?"$ Z
:6Pnie
>Q=Ukn;k
Utility.log(nFileLength); d8E,o7$m
|g<*Rk0
i?;R}%~
return nFileLength; Cp^g'&
} wz#A1F
z1vw'VT>
Ql &0O27
//保存下载信息（文件指针位置） 'z5h3J
private void write_nPos() \vCGU>UY
{ DI,K(_@G
try{ XX2h(-
output = new DataOutputStream(new FileOutputStream(tmpFile)); h0Ee?=
output.writeInt(nStartPos.length); EY=FDlV
for(int i=0;i<nStartPos.length;i++) 7)^:8I(
{ i)8N(HN
// output.writeLong(nPos); #f*g]p{
output.writeLong(fileSplitterFetch.nStartPos); >&WhQhZ3kg
output.writeLong(fileSplitterFetch.nEndPos); ,."b3wR[w
} ZYcd.?:6
output.close(); C#;@y|Rw
} R{?vQsLk
catch(IOException e){e.printStackTrace ();} jJBnDxsA
catch(Exception e){e.printStackTrace ();} ?gSSli[
} R^%e1KO]
+}aC-&
[ ]^X`R
//读取保存的下载信息（文件指针位置） FRZs[\I|iT
private void read_nPos() g$FEEDF
{ 5wT>N46UX
try{ Qf xH9_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); d"ZU y!a
int nCount = input.readInt(); )\ZzTS
nStartPos = new long[nCount]; 7?nJ4x1
nEndPos = new long[nCount]; dlDki.
for(int i=0;i<nStartPos.length;i++) ufrqsv]=
{ Bu3T/m
nStartPos = input.readLong(); KKEN'-3
nEndPos = input.readLong(); >o~Z>lr
} =P`~t<ajB
input.close(); \:v$ZEDJ>
} c*;7yh&%
catch(IOException e){e.printStackTrace ();} %}&(h/= e
catch(Exception e){e.printStackTrace ();} S&(^<gwl
} ^$-Ye]<
r?A|d.Tl
\.#p_U5In
private void processErrorCode(int nErrorCode) A&,,9G<
{ ]|U-y645
System.err.println("Error Code : " + nErrorCode); ECcZz.
} l&W;b6L
bk<FL6z z
KrcgIB8X
//停止文件下载 A6{b?aQ
public void siteStop() B=X,7
{ #yW\5)
bStop = true; o>?*X(+le
for(int i=0;i<nStartPos.length;i++) ~@4'HMQ
fileSplitterFetch.splitterStop(); syPWs57pH
.lNs4e
jb[!E^'&>
} `/nM[
} Y<f_`h^r
//负责部分文件的抓取 iqwkARG"
**FileSplitterFetch.java %gd(wzco
*/ mC[UXN/
package NetFox; -*a?<ES`
MCc$TttaVz
u~1o(Zn =
import java.io.*; T$+-IAE
import java.net.*; _&#S@aGw
|Au]1}
L}sx<=8.m
public class FileSplitterFetch extends Thread { g{:<2xI5P
RJ4. kt
PRB{VC<k
String sURL; //File URL l=}~v
long nStartPos; //File Snippet Start Position IQH[Q9%
long nEndPos; //File Snippet End Position bb-qO#E
int nThreadID; //Thread's ID g(ogXA1
boolean bDownOver = false; //Downing is over v [njdP
boolean bStop = false; //Stop identical e]Fp=*#
FileAccessI fileAccessI = null; //File Access interface Sr_VL:Gg
dy>!KO
bh p5<N
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException IMGP'g
{ A,gEM4
this.sURL = sURL; beXNrf=bG
this.nStartPos = nStart; sJG5/w
this.nEndPos = nEnd; hk>;pU(
nThreadID = id; MJ{%4S{K,p
fileAccessI = new FileAccessI(sName,nStartPos);//定位 )ChqATKg
} Ts$@s^S]
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[KJ q
public void run() q,>?QBct*
{ YDC&u8
while(nStartPos < nEndPos && !bStop) ZD>a>]
{ TX [%(ft
ciQZHH2
^|MjJsn
try{ Q{g;J`Z)p
URL url = new URL(sURL); @>Mxwpl?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2aN<w'pA
httpConnection.setRequestProperty("User-Agent","NetFox"); U/l?>lOD\
String sProperty = "bytes="+nStartPos+"-"; BX+.0M
httpConnection.setRequestProperty("RANGE",sProperty); _-TA{21)
Utility.log(sProperty); BB$oq'
?sz)J3
lfZ04M{2
InputStream input = httpConnection.getInputStream(); gB'fFkd
//logResponseHead(httpConnection); M]]pTU((
#/2$+x
t2HJsMX
byte[] b = new byte[1024]; [K/m
int nRead; tWeFEVg
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >slm$~rv
{ 5Por "&%
nStartPos += fileAccessI.write(b,0,nRead); }J:+{4Yn
//if(nThreadID == 1) 5N[9 vW
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Z;l`YK^-
} Ev"|FTI/
_ *f
``VW;l{
Utility.log("Thread " + nThreadID + " is over!"); k^"bLf(4
bDownOver = true; \!]hU%Un
//nPos = fileAccessI.write (b,0,nRead); kX`[Y@nUN
} j=?'4sF
catch(Exception e){e.printStackTrace ();} K14^JAdY/
} M=qb^~ l
} 1 rs&74-
DV)3
pCh2SQ(Q>
//打印回应的头信息 -s|8<A||"
public void logResponseHead(HttpURLConnection con) J(4"S o_
{ d?AlI
for(int i=1;;i++) Sq\(pfvo
{ ^~`?>}MJ
String header=con.getHeaderFieldKey(i); 2dp>Z",
if(header!=null) wr(*?p]R
//responseHeaders.put(header,httpConnection.getHeaderField(header)); U6E\AvbRn
Utility.log(header+" : "+con.getHeaderField(header)); 0|&\'{
else 8lF\v/vN
break; 1NQbl+w#I
} lKWPTCU
} FTc.]laO
mrIh0B:`
7\]E~/g
public void splitterStop() 7/7Z`
{ sg'pO*_&
bStop = true; /S5|wNu
} <@wj7\pQ
W&(k!6<x
!-`Cp3gqHr
} *]hBGr#6
7>iU1zy
g V5zSudW
/* D8&`R
**FileAccess.java ,Ys"W x
*//文件访问(定位，写) 3pf[M{dG
package NetFox; y[B>~m8$
import java.io.*; nOx4<Wk&
nJ4pTOc
F
public class FileAccessI implements Serializable{ \^I>Q_LU
q9w~A-Oh`1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 RrUBpqA
RandomAccessFile oSavedFile; bVP"(H]
long nPos; rc&%m
_@S`5;4x
|@NiW\O
public FileAccessI() throws IOException T91moRv
{ niB`2J
this("",0); gs!(;N\j|
} w 4[{2
!*- >;:9B
4DZ-bt'
public FileAccessI(String sName,long nPos) throws IOException *5w{8
{ 4_Dp+^JF
oSavedFile = new RandomAccessFile(sName,"rw"); ()&~@1U
this.nPos = nPos; wtje(z5IL
oSavedFile.seek(nPos); Eu"_MgD
} 'y8]_K*
U9b?i$
.bBdQpF-
public synchronized int write(byte[] b,int nStart,int nLen) Y0eE-5F,
{ 4pw6bK,s2\
int n = -1; q6YXM
try{ )K &(
oSavedFile.write(b,nStart,nLen); MSf;ZB
n = nLen; ;M"9$M'
} N F)~W#
catch(IOException e) dOa%9[
{ jKt7M>P
e.printStackTrace (); Eke5Nb
} 6Gf?m;
2eMTxwt*S
jLg9H/w{
return n; A}eOFu`
} *_>Lmm.yh
B)d(TP,>
pz"0J_xDM
} bygx]RC[
<&C]sb
iY21Ql%
/* J2:y6kGj>
**SiteInfoBean.java &b:1I7Cp*
*/ \rv<$d@L
package NetFox; t!RiUZAo
!47n[Zs
<[w=TdCPs
public class SiteInfoBean { #%DE;
):iA\A5q[
-GxaV #{
private String sSiteURL; //Site's URL m*JaXa
private String sFilePath; //Saved File's Path Hh+ 2mkg
private String sFileName; //Saved File's Name eM8}X[
private int nSplitter; //Count of Splited Downloading File '-zD
dAuJXGo
82l~G;.n3
public SiteInfoBean() &jmRA';sK
{//nSplitter的缺省值为5 K6R.@BMN
//default value of nSplitter is 5 TYW&!sm
this("","","",5); wmTb97o
} .9wk@C(Eh_
=?!wXOg_
;+"+3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) \ Yx/(e
{ %7|9sQ:
sSiteURL= sURL; rW$[DdFA5{
sFilePath = sPath; s0vDHkf8
sFileName = sName; \-g)T}g,I
this.nSplitter = nSpiltter; |ZmUNiAa
VVlr*`
q<M2,YrbAI
} jyCXJa-!-
q@{Bt{$x
lnjXDoVb<
public String getSSiteURL() 5 sX+~Q
{ vam;4vyu
return sSiteURL; 5aCgjA11
} ?`?)QE8
094o'k
*WuID2cOI
public void setSSiteURL(String value) zolt$p
{ PpzP7
sSiteURL = value; 'tH_p
} s%W C/ZK
m^zUmrj[
?{[ v+t#
public String getSFilePath() J\b^)
{ y gz6C
return sFilePath; A*\.NTM
} z:wutqru
:;9F>?VN>0
r8RoE`/T
public void setSFilePath(String value) ,>%}B3O:Y=
{ F'21jy&
sFilePath = value; K|[*t~59
} 2GDD!w#!j
.:F%_dS D
%xI p5h]
public String getSFileName() p;>ec:z3M
{ @J/K-.r
return sFileName; XwJ7|cB
} "]} bFO7C
dl.p\t(1
3ca (i/c
public void setSFileName(String value) %WjXg:R
{ [DI+~F
sFileName = value; ?82xdpg
} 7fZDsj:
Wi)_H$KII
9dx/hFA
public int getNSplitter() |Y,b?*UF
{ Hquc o
return nSplitter; bKMy|_
} Hx?;fl'G%
X aMJDa|M
W_"sM0 w
public void setNSplitter(int nCount) g,!L$,/F
{ ?Lk)gO^C
nSplitter = nCount; \"P%`C
} V2wb%;q
} sBT2j~jhJ
[M=7M}f;
ig/xv
/* !$gR{XH$]
**Utility.java GjvOM y
*/ N5lDS
package NetFox; Pd_U7&w,5
8}O lL,fP
at,XB.}Z]
public class Utility { 4O^xY 6m
8;JWK3Gv
'-Vt|O_Q
public Utility() .1Dg s=|
{ )vE~'W
t.i 8 2Q
D2Kp|F;
} tEvut=k'
*0Skd
//线程睡眠 vApIHI?-
public static void sleep(int nSecond) G[uK-U
{ (x;@%:3j$
try{ nFHUy9q
Thread.sleep(nSecond); "R;U/+
} 8;RUf~q?
catch(Exception e) K0|FY=#2y
{ W}@c|d $`
e.printStackTrace (); aC8} d
} 3u+T~g0^
} U:0mp"
V^bwXr4f
//日志 6 ob@[ @
public static void log(String sMsg) p>v$FiV2N
{ ^@s1Z7
System.err.println(sMsg); Ot_]3:`J~
} 6]WAUK%h
|\pj;XU
h+g_rvIG*
public static void log(int sMsg) t%/&c::(6
{ JcsHt;
System.err.println(sMsg); Z&+ g;(g
} /[ 5gX^A
} On9A U:\
6*78cg Io
FXG]LoP
/* "c%0P"u
**TestMethod.java FrfM3x6UM
*/ gwuI-d^
package NetFox; d;Ym=YHJtn
823Y\x~>
Q4#m\KK;i9
public class TestMethod { _{YWXRC#
/K@XzwM
M=@:ZQ^!
public TestMethod() K7_UP&`=J
{ ///xx/weblogic60b2_win.exe c<B/V0]
try{ uP)'FI
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6_GhO@lOG
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); itt3.:y
SiteFileFetch fileFetch = new SiteFileFetch(bean); S6Q
fileFetch.start(); -">;-3,K
} u5`u>.!
catch(Exception e){e.printStackTrace ();} Q%`@0#"]Sv
t6"%3#s
r= `Jn6@
} ^1I19q
|.: q
RB7tmJc
public static void main(String[] args) ^,TO#%$iE
{ MS~(D.@ZS
new TestMethod(); Y8~"vuIE5
} 'x#~'v*
} f643#1
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