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)); spm)X-[1
} ,j`48S@
for(int i=0;i<nEndPos.length-1;i++) eGg6wd
{ B+~ /-3
nEndPos = nStartPos[i+1]; c1i:m'b_5
} 1$Q[%9
nEndPos[nEndPos.length-1] = nFileLength; %i/|}K
} mRC3w(W
} :<B_V<
$z*"@
,g}$u'A+d
//启动子线程 j!!s>7IZ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 0wNlt#G;{
for(int i=0;i<nStartPos.length;i++) xg7KU&
{ =O"]e/CfO
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), u6?9#L(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), *S.FM.r
nStartPos,nEndPos,i); 8@LWg d
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x:~XZX\mwH
fileSplitterFetch.start(); Rvu5#_P
} %Rf9KQ
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 60{DR >S
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); cf$ hIB)Oi
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", /3rNX}tOMH
nEndPos = " + nFileLength); 2jC:uk
// fileSplitterFetch[nPos.length-1].start(); ogQfzk
Z}0xK6
gsEcvkj*
//等待子线程结束 LFxk.-{=
//int count = 0; \+sa[jK
//是否结束while循环 ;A@DE@^5w
boolean breakWhile = false; F.aG7
N0^SWA|S
bri8o"
while(!bStop) +aEm]=3
{ $ -<(geI
write_nPos(); ^yc8is'`
Utility.sleep(500); )4qspy3
breakWhile = true; 0\Jeyb2dl
"|dhmV[;
?)(/SZC0
for(int i=0;i<nStartPos.length;i++) ]o"E4Vht
{ )V>OND
if(!fileSplitterFetch.bDownOver) |hi,]D^Kc
{ fVY I
breakWhile = false; G8__6v~
break; SE'|||B
} i}C%8}%
} !e<2o2~.
if(breakWhile) z8"1*V
break; ReM]I<WuY
v9r.w-
:;hg :Q:
//count++; [sk n9$
//if(count>4) ({C[RsY=6
// siteStop(); :7.k E
} !lFNG:&`
`i(b%$|^&Z
@J5TDq @
System.err.println("文件下载结束！"); B=n90XO |
} j #: ARb
catch(Exception e){e.printStackTrace ();} p6BDhT(RS
} xFThs,w
Z8ivw\|M8
h x5M)8#+
//获得文件长度 CYE[$*g6y
public long getFileSize() x"C7NW[$
{ R+K|K2"
int nFileLength = -1; yF6AI@y
try{ W/t,7lPFb
URL url = new URL(siteInfoBean.getSSiteURL()); c u";rnj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 2 yANf
httpConnection.setRequestProperty("User-Agent","NetFox"); :/5GHfyj
3V^5 4_
/({oN1X>i
int responseCode=httpConnection.getResponseCode(); @XtrC|dkkE
if(responseCode>=400) _{#K
{ y>E:]#F
processErrorCode(responseCode); @73kry v
return -2; //-2 represent access is error `kvIw,c.
} {Y2J:x
LVdR,'lS
mejNa(D ^
String sHeader; PIo@B|W-SX
=8*ru\L:hr
m='}t \=
for(int i=1;;i++) ']\SX*z?
{ t,/8U
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); +L'Cbv="
//Utility.log(in.readLine()); g)$KN,gGuO
sHeader=httpConnection.getHeaderFieldKey(i); cU ?F D
if(sHeader!=null) (X\]!'A
{ : KFK2yD
if(sHeader.equals("Content-Length")) L?|}!
{ `w>D6K+
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); v,QvCozOz
break; l/nBin&YGv
} {`M\}(E
} e&T-GL
else RR+kjK?
break; P/WGB~NH
} @uV]7d"z(
} M1NdlAAf
catch(IOException e){e.printStackTrace ();} D~i5E9s5
catch(Exception e){e.printStackTrace ();} !Z\Gv1
3`{ vx
rloxM~7!,)
Utility.log(nFileLength); j<BRaT
GLZ*5kw
NhNd+SCZ@
return nFileLength; VKYljY0#
} b|Ge#o
C_q2bI
oO3^9?Z
//保存下载信息（文件指针位置） svxjad@l/
private void write_nPos() ge?0>UU;~
{ }|;j2'(R
try{ CFW Hih
output = new DataOutputStream(new FileOutputStream(tmpFile)); W"vkmk
output.writeInt(nStartPos.length); >m!Z$m([J
for(int i=0;i<nStartPos.length;i++) 0iR?r+|
{ 3[_WTwX0
// output.writeLong(nPos); PbS1`8|4
output.writeLong(fileSplitterFetch.nStartPos); *3={s"a.(
output.writeLong(fileSplitterFetch.nEndPos); v_U/0 0
} &XI9%h9|
output.close(); {2Tu_2>
} X|!@%wuGC
catch(IOException e){e.printStackTrace ();} >vXJ9\
catch(Exception e){e.printStackTrace ();} [) >Yp-n
} C}3a^j
l4taD!WD/
jP}Ry=V/
//读取保存的下载信息（文件指针位置） +0*\q
private void read_nPos() I!9>"s12
{ )[UYCx'
try{ -W@nc QL}
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); K+M\E[1W
int nCount = input.readInt(); N\.g+ W
nStartPos = new long[nCount]; "'Gq4<&y
nEndPos = new long[nCount]; F,VWi$Po\N
for(int i=0;i<nStartPos.length;i++) \/SOpC
{ SD%3B!cpX
nStartPos = input.readLong(); Fz<1xyc(
nEndPos = input.readLong(); .9z}S=ZK
} 1~E4]Ef:W
input.close(); @mg5vt!$`
} 2g5 4<G*e
catch(IOException e){e.printStackTrace ();} V,c^Vqy
catch(Exception e){e.printStackTrace ();} '?.']U,: $
} Ho(}_Q&
I H#CaD
*>[q*SF
private void processErrorCode(int nErrorCode) Z<AZO ^
{ bYem0hzOe
System.err.println("Error Code : " + nErrorCode); V(LfFO{^>?
} ZR|s]'
:?z@T[-
u-jc8W`Zd
//停止文件下载 B+R|fQ
public void siteStop() Z]2z*XD
{ N`H`\+
bStop = true; <Tbl|9
for(int i=0;i<nStartPos.length;i++) p^w)@^f
fileSplitterFetch.splitterStop(); rbv
J~`!@!
3rN}iSF^
} L_:~{jV
} &Y9%Y/Y
//负责部分文件的抓取 %1GKN|7
**FileSplitterFetch.java p(4B"[!S
*/ T.;U~<
package NetFox; ?kV_!2U)'K
Uh1UZ r
';.y`{/
import java.io.*; }c=Y<Cdh
import java.net.*; \0;w7tdo
g co;8e_
n,-*$~{
public class FileSplitterFetch extends Thread { Mkt_pr
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6kR3[]:16v
String sURL; //File URL o,J8n;"l
long nStartPos; //File Snippet Start Position V^n=@CZT9C
long nEndPos; //File Snippet End Position %)dp a
int nThreadID; //Thread's ID x+'Ea.^
boolean bDownOver = false; //Downing is over kDQE*o
boolean bStop = false; //Stop identical !,b&e
FileAccessI fileAccessI = null; //File Access interface MZX@Gi<S[
C~.\2D`zy
cR55,DR,#W
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ih75C"
{ 5__B M5|
this.sURL = sURL; V}2[chbl
this.nStartPos = nStart; ?uP5("c
this.nEndPos = nEnd; i~<.@&vt
nThreadID = id; &"Cy&[
fileAccessI = new FileAccessI(sName,nStartPos);//定位 x2b t^!t.
} Ag(JSVY
\7$"i5
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public void run() } 21!b :a
{ cL#zE
while(nStartPos < nEndPos && !bStop) OQg}E@LZ
{ 4 s9^%K\8{
Edcv>}PfE
|?f~T"|>
try{ T(cpU,Q
URL url = new URL(sURL); %7\l+g,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); O\]{6+$fm!
httpConnection.setRequestProperty("User-Agent","NetFox"); &i`(y>\
String sProperty = "bytes="+nStartPos+"-"; wF6a*b@v
httpConnection.setRequestProperty("RANGE",sProperty); #X{lV]Z
Utility.log(sProperty); ,ag* /
R Eo{E
{VM^K1
InputStream input = httpConnection.getInputStream(); C\bJ_vl;'
//logResponseHead(httpConnection); mB bGj3u;
mL;oR4{
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byte[] b = new byte[1024]; 4/S3hH
int nRead; 7g oRj
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) u-.nR}DM_
{ rT4qx2u
nStartPos += fileAccessI.write(b,0,nRead); g*4^HbVxt
//if(nThreadID == 1) _IxYnm`pc
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !@T~m1L eY
} mpIR: Im
mv$gL
{Ov{O,c5
Utility.log("Thread " + nThreadID + " is over!"); &f)pU>Di
bDownOver = true; XA69t2J~F
//nPos = fileAccessI.write (b,0,nRead); Ne1W!0YLK
} aE:$ N#|Qa
catch(Exception e){e.printStackTrace ();} Wn2J]BH
} jEP'jib%
} =6fJUy^M\
,K&L/*
UhU+vy6)/
//打印回应的头信息 -"2%+S{
public void logResponseHead(HttpURLConnection con) t|UM2h
{ n5fc_N/8O=
for(int i=1;;i++) nU2w\(3|
{ 2j{T8F\]
String header=con.getHeaderFieldKey(i); }^odUIj
if(header!=null) ^Vc(oa&;
//responseHeaders.put(header,httpConnection.getHeaderField(header)); $c+:dO|Fb
Utility.log(header+" : "+con.getHeaderField(header)); A*]sN8
else JRtDjZ4>
break; LTb#1JC
} iWe'|Br
} ue!4By8T
N{Pa&/V
7<?Aou
public void splitterStop() S[&yO-=p6
{ $TAsb>W!(
bStop = true; /|v b)J
} a72L%oJ
m'ZxmsFo
ehMpo BL
} 4/2@^\?i)
99~-TiU
bl|)/)6o
/* PvxU.
**FileAccess.java mMK 93Ng"&
*//文件访问(定位，写) VZk;{
package NetFox; pWoeF=+y]W
import java.io.*; JY D\VaW
ZRa~miKyM
.SWn/Kk
public class FileAccessI implements Serializable{ @.QuIm8,
QT(]S>--n
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !]z4'*)W
RandomAccessFile oSavedFile; O&dh<
long nPos; ]4\6_J&
%w3tzE1Hq
7U&<{U<
public FileAccessI() throws IOException `]/0&S
{ q-+_Y `_\
this("",0); ]^QO^{Sz
} mw\Pv|
4%SA%]a L1
}$3pS:_N~
public FileAccessI(String sName,long nPos) throws IOException \LM{.gzT
{ .;:dG
oSavedFile = new RandomAccessFile(sName,"rw"); J p0j
this.nPos = nPos; T&E'MB
oSavedFile.seek(nPos); &w^:nVgl
} #<-%%
*Oh]I|?
0\o5+
public synchronized int write(byte[] b,int nStart,int nLen) qcBamf
{ *OY Nx4k
int n = -1; (Ii+}Mfp
try{ e{ZS"e`!
oSavedFile.write(b,nStart,nLen); ^8g<>,$
n = nLen; <7MxI@\
} :*tFW~<*b
catch(IOException e) !WD^To
{ A=wh&X
e.printStackTrace (); msZ3%L
} ~8lB#NuN
m{rsjdnA
#\3X;{
return n; ev5m(wR
} 0(^N
$ 3.Y2&$T
Y0o{@)Y:
} eqU y>
7<93n`byM
(S63:q&g
/* :CXm@yF~4=
**SiteInfoBean.java f(c#1AJE53
*/ mqQC`Aqx:
package NetFox; @dhnpR:L
A+"'8%o9}
Es1T{<G|w
public class SiteInfoBean { *HQ>tvUh
zi+NQOhR
"Q1oSpF
private String sSiteURL; //Site's URL W`jKe-jF
private String sFilePath; //Saved File's Path zm=|#f
private String sFileName; //Saved File's Name 9f3rMPVh(
private int nSplitter; //Count of Splited Downloading File +!-U+W
!<5Wi)*
4 :M}Vz-
public SiteInfoBean() TmLfH d
{//nSplitter的缺省值为5 1Zgv+.
//default value of nSplitter is 5 2-@z-XKn
this("","","",5); F@-8J?Hl:
} 4{ED~w|
mFuHZ)iQG
i[n3ILn
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }^*m0`H
{ xyi4U(;
sSiteURL= sURL; /}3I:aJwb
sFilePath = sPath; >u?a#5R:m
sFileName = sName; b}m@2DR'|m
this.nSplitter = nSpiltter; f/^T:F6
,egbU(:l
~PedR=Y0n
} i$XT Qr0K=
u 236a\:
3^Z@fC
public String getSSiteURL() R"O,2+@<.
{ Ev1gzHd!i
return sSiteURL; mS &^xWPV
} 8}|!p>
l }]"X@&G
[}?E,1Q3
public void setSSiteURL(String value) Lz`_&&6
{ "V<7X%LIX
sSiteURL = value; _16r8r$V
} D#d \1g
'TDp%s*;
L=kETJ:g
public String getSFilePath() $`"$ZI6[
{ d5lD!
return sFilePath; K5(:0Q.5y
} uP2Wy3`V
KzLkT7,y+
#}C6}};
public void setSFilePath(String value) \m~Oaf;$
{ H:,Hr_;nC
sFilePath = value; FLaj|Z~#)
} W$Z8AZ{E
.-.b:gdO(
CWS]821;
public String getSFileName() cjf_,x
{ LTnbBh*mc
return sFileName; G5!!^p~
} }ZfdjF8N!
+Sg+% 8T
UkM#uKr:
public void setSFileName(String value) r.v.y[u
{ He LW*
sFileName = value; Ap!i-E,"J
} !w:pb7+G
E#c9n%E\sz
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public int getNSplitter() rVDOco+w
{ 2mfG:^^c
return nSplitter; x3 01uf[
} (kSb74*g
Vu Ey`c
1cd3m
public void setNSplitter(int nCount) FdS'0#$
{ jluv}*If
nSplitter = nCount; O2oF\E_6
} Twpk@2=l
} '$q3Ze
q 7hoI]
uUh6/=y
/* MUMB\K*$
**Utility.java F2dwT
*/ !>6`+$=U
package NetFox; ]|B_3*A
p}|<EL}Z9
H.)J?3
public class Utility { G PL^!_
G(#EW+
!r9~K^EI
public Utility() 3tCT"UvTD
{ v'SqH,=d
Cuo"6, M
-5,+gakSk
} sJm v{wM
6Bn}W ?
//线程睡眠 Dx.hM[
public static void sleep(int nSecond) DN|+d{^lN
{ 1A N)%
try{ NX?6 (lO,
Thread.sleep(nSecond); dXDuO
} Q VWVZ >l
catch(Exception e) -z>m]YDH
{ SHqz&2u
e.printStackTrace (); N`7+]T
} /n3SE0Y
} \d QRQL{LL
qmq#(%Z <W
//日志 #kAk d-QY6
public static void log(String sMsg) ?)e6:T(
{ 'o1lJ?~kH
System.err.println(sMsg); z"V`8D
} d@ tD0s
1c:/c|shQ_
/B5rWJ2AS
public static void log(int sMsg) 2o~UA\:+=
{ e(jD[q
System.err.println(sMsg); "_ON0._(/
} Ob|v$C
} 9zaSA,}
7lG,.W|
z<8WN[fB
/* 6V-JyTcxGI
**TestMethod.java ;:P}s4p
*/ 3+V.9TL'a
package NetFox; UZu.B!4
.wkW<F7
p}q]GJ
public class TestMethod { vJuL+'[i
T_<:
h]k1vp)Q y
public TestMethod() ^6 \@$
{ ///xx/weblogic60b2_win.exe Uk4G9}I
try{ x6 h53R
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); M(W-\L
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); m<|fdS'@
SiteFileFetch fileFetch = new SiteFileFetch(bean); `6o5[2V
fileFetch.start(); R5fZ}C7
} sb</-']a
catch(Exception e){e.printStackTrace ();} i[PksT#p
1"U.-I@
pYX!l:hk
} b&.3uls6
*m`F-J6U
g3\13<
public static void main(String[] args) -@/!u9l
{ r1.OLn?C
new TestMethod(); O @{<?[
} c~ Q5A
} I3dUI~}u
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