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)); w&H ?;1
} V^0*S=N
for(int i=0;i<nEndPos.length-1;i++) z!1j8o2
{ -r,J>2`l
nEndPos = nStartPos[i+1]; 06ueE\@Sg
} Q`oi=OYB
nEndPos[nEndPos.length-1] = nFileLength; :?S2s Ne2
} z><JbSE?
} Ri,UHI4 W
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>Z3}WMgBN
//启动子线程 Pc$<Cv|vz
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; LHacHv
for(int i=0;i<nStartPos.length;i++) +(<CE#bb[
{ <1@_MYo
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8U8"k
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), KctD=6
nStartPos,nEndPos,i); ,og@}gOMB
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [<%yUy
fileSplitterFetch.start(); Bf7RW[ -v
} s=6w-'; V
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~U^0z|.
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); jR48.W
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", P#yS]F/
nEndPos = " + nFileLength); 2L,e\]2Z
// fileSplitterFetch[nPos.length-1].start(); @z2RMEC~
0nl)0|?Az
l&C%oW
//等待子线程结束 b'ew Od=
//int count = 0; hslJs^
//是否结束while循环 E7*]t_p"
boolean breakWhile = false; u?aq' "t
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while(!bStop) KDY~9?}TM
{ =GLsoc-b
write_nPos(); +ivz
Utility.sleep(500); K_My4>~Il
breakWhile = true; R{*p\;
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sd=i!r)ya
for(int i=0;i<nStartPos.length;i++) ;z[yNW8
{ *{tJ3<t(1
if(!fileSplitterFetch.bDownOver) Cd(Ov5%
{ -nU_eDy
breakWhile = false; PCFm@S@Q
break; a @TAUJ,
} -Y+[`0$'
} b?Vu9!
if(breakWhile) ~=c#Ff=Z
break; vF*H5\ m<a
jOe %_R
tBf u{oC
//count++; 9t)t-t#P;
//if(count>4) y[}BFUy
// siteStop(); 20K<}:5t1
} AU >d1S.
tw.%'oJ7
qg'm<[
System.err.println("文件下载结束！"); yJgnw6>r2
} gzuM>lf*{
catch(Exception e){e.printStackTrace ();} 1ra}^H}
} {wd.aUB
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#$#{QEh0}
//获得文件长度 578Dl(I#)
public long getFileSize() t<$yxD/R
{ ;xs?^N|
int nFileLength = -1; |_2O:7qe
try{ M>'-P
URL url = new URL(siteInfoBean.getSSiteURL()); lv{Qn~\y&
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); (D))?jnC
httpConnection.setRequestProperty("User-Agent","NetFox"); AJq'~fC;I
4}l,|7_&I
esxU44
int responseCode=httpConnection.getResponseCode(); 56L>tP
if(responseCode>=400) y/Nvts2!C
{ &&tQ,5H5
processErrorCode(responseCode); }G-qOt
return -2; //-2 represent access is error psYfz)1;
} rYc?y
lKe aI
f9#B(4Tgi
String sHeader; BPC$ v\a
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)L^WD$"'Q
for(int i=1;;i++) :egSW2"5S
{ whvM^
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); agt7b@-5=
//Utility.log(in.readLine()); 8;+t.{
sHeader=httpConnection.getHeaderFieldKey(i); -B@jQg@ >
if(sHeader!=null) ncu> @K$n
{ 20hE)!A
if(sHeader.equals("Content-Length")) /X8b=:h
{ }!B<MGBd
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); C[wnor!
break; iT IW;Cv
} V_0e/7}Ya
} II),m8G
else =#uXO<
break; "j~=YW+l
} 9t;aJFI
} rMLCtGi
catch(IOException e){e.printStackTrace ();} Kx#G_N@
catch(Exception e){e.printStackTrace ();} nfl6`)oW
Is-Kz}4L
UD"e:O_
Utility.log(nFileLength); -6Cxz./#yS
JTdK\A>l
KLbP;:sr
return nFileLength; oA73\BFfP
} #B>Hq~ vrC
7CNEP2}:R
]%G[<zD,1
//保存下载信息（文件指针位置） Pbz-I3+66
private void write_nPos() ]`+>{Sx 1
{ a*=\-;HaZ
try{ dB< \X.
output = new DataOutputStream(new FileOutputStream(tmpFile)); U4M!RdG
output.writeInt(nStartPos.length); zYF'XB]4
for(int i=0;i<nStartPos.length;i++) &W}ooGg
{ AnIENJ
// output.writeLong(nPos); 3\6jzD
output.writeLong(fileSplitterFetch.nStartPos); :0#!=
output.writeLong(fileSplitterFetch.nEndPos); eF:6k qg
} G4ZeO:r
output.close(); :m-HHWMN
} 6ffrV
catch(IOException e){e.printStackTrace ();} 2Xgn[oI{
catch(Exception e){e.printStackTrace ();} 5a-8/.}cP
} t3G%}d?
v@< "b U
FWPkvL
//读取保存的下载信息（文件指针位置） #2Mz.=#G
private void read_nPos() nwW`Q>+#U
{ aS:17+!
try{ HOXqIZN85
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 5Sk87o1E(d
int nCount = input.readInt(); qH"e: wgL
nStartPos = new long[nCount]; L +-B,466
nEndPos = new long[nCount]; { 5h6nYu
for(int i=0;i<nStartPos.length;i++) 5(TI2,4
{ _?`3zm4
nStartPos = input.readLong(); #jK{)%}mA
nEndPos = input.readLong(); yQ6{-:`)
} 9/q4]%`
input.close(); ]Jm9D=
} =suj3.
catch(IOException e){e.printStackTrace ();} 8vc4J5
catch(Exception e){e.printStackTrace ();} P2f~sx9
} A+:K!|w
Rnun() plJ
p4|:u[:&
private void processErrorCode(int nErrorCode) eDIjcZ
{ ld`oIEj!P_
System.err.println("Error Code : " + nErrorCode); c tTbvXP
} )|'? uN7
CP/`ON
+-`Q}~s+
//停止文件下载 kLADd"C
public void siteStop() KZ;U6TBiB
{ sR'rY[^/|
bStop = true; 3|g'1X}
for(int i=0;i<nStartPos.length;i++) Y#NlbKkzu
fileSplitterFetch.splitterStop(); Y!CZ?c)@
HrWXPac A
HI)ks~E/
} xOPSw|!w
} 44($a9oa2
//负责部分文件的抓取 dt^yEapjM
**FileSplitterFetch.java FpCj$y~3
*/ N]}L*o&
package NetFox; X62z>mM
xlv:+
3-~_F*%ST
import java.io.*; C5 ^_R
import java.net.*; 86.!sQ8b
J4xt!RW!
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public class FileSplitterFetch extends Thread { k7f[aM5]
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String sURL; //File URL H Viu7kue`
long nStartPos; //File Snippet Start Position p"JITH:G
long nEndPos; //File Snippet End Position hFyN|Dqhds
int nThreadID; //Thread's ID U7bG(?k)
boolean bDownOver = false; //Downing is over <o^mQq&
boolean bStop = false; //Stop identical ^4c2}>f
FileAccessI fileAccessI = null; //File Access interface D?8t'3no
R qOEQ*k
M\>y&'J-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ,N5Rdgzk
{ W^P%k:anK
this.sURL = sURL; |`E\$|\p
this.nStartPos = nStart; Uiv;0Tovl
this.nEndPos = nEnd; ^kt#[N
nThreadID = id; 7Ja^d-F7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 @X
} ,dK%[
{;=+#QK/
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public void run() _av%`bb&z9
{ x{5I
while(nStartPos < nEndPos && !bStop) R8O<}>3a
{ @fPiGu`L
wa@X^]D8
sW@4r/F>:D
try{ %fK"g2:
URL url = new URL(sURL); 2pxl!
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); }m\
httpConnection.setRequestProperty("User-Agent","NetFox"); }eULcgRG
String sProperty = "bytes="+nStartPos+"-"; M I/9?B
httpConnection.setRequestProperty("RANGE",sProperty); 5 S7\m5
Utility.log(sProperty); \ bd? `."
//_v"dqP{)
8.'%wOU@A
InputStream input = httpConnection.getInputStream(); d+ql@e]
//logResponseHead(httpConnection); s <Ag8U8
UTHGjE
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byte[] b = new byte[1024]; 3:dQN;=
int nRead; y[.0L!C {
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ~,m6g&>R
{ pU<->d;->
nStartPos += fileAccessI.write(b,0,nRead); 6*tI~
//if(nThreadID == 1) r}pYm'e
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pV:X_M6
} NcB^qv
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Utility.log("Thread " + nThreadID + " is over!"); A ElNf:
bDownOver = true; . p<*n6E
//nPos = fileAccessI.write (b,0,nRead); 2{| U
} !C&}e8M|eX
catch(Exception e){e.printStackTrace ();} }+,1G!?z
} {LrezE4
} svHs&v
4B^f"6'
AQ'~EbH(
//打印回应的头信息 z;2kKQZm
public void logResponseHead(HttpURLConnection con) P8:k"i/6J
{ u4rGe!
for(int i=1;;i++) A@f`g[q
{ k`'^e/
String header=con.getHeaderFieldKey(i); cK1r9ED|
if(header!=null) ;[uJ~7e3
//responseHeaders.put(header,httpConnection.getHeaderField(header)); yAW%y
Utility.log(header+" : "+con.getHeaderField(header)); <t.yn\G-w
else EO:i+e]=
break; CRw.UC\
} o/)]z
} "tn]s>iAd=
1<Qb"FN!2
ri.;&
public void splitterStop() ApG_Gd.
{ 4pduzO'I
bStop = true; a>ZV'~zTf
} !Hr~B.f7
&?#V*-;^
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} @9~6+BZOq
zw_Xh~4"b
UQ}[2x(Kb
/* LeF Z%y)F
**FileAccess.java Z[[qW f
*//文件访问(定位，写) )4bBR@QM
package NetFox; s%1O}X$c
import java.io.*; qm{(.b^
}} J?, >g
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public class FileAccessI implements Serializable{ `gDpb.=Y
J4;w9[a$
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 H"=%|/1M0
RandomAccessFile oSavedFile; kD8$ir'UYG
long nPos; ^yb3L1y
Rr{mD#+
X6)-1.T&
public FileAccessI() throws IOException @4#q
{ 6k|o<`~,
this("",0); _)"-zbh}{
} 8iGS=M
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"3(""0Q
public FileAccessI(String sName,long nPos) throws IOException SIYBMe
{ ;:4&nJ*qG
oSavedFile = new RandomAccessFile(sName,"rw"); 2FU+o\1%
this.nPos = nPos; `u$ Rd
oSavedFile.seek(nPos); lR5[UKr
} f>!)y-7
hjf!FY*F
b+Sq[
public synchronized int write(byte[] b,int nStart,int nLen) `?f6~$1
{ [U]^:sV)
int n = -1; 'K&^y%~py,
try{ d!0iv'^t
oSavedFile.write(b,nStart,nLen); Z.'j7(tu
n = nLen; \kWL:uU
} (+uM |a
catch(IOException e) W>TG!R 5
{ ~wYGTm=(n
e.printStackTrace (); uDD{O~wF,
} V6Z~#=EQ
3E9 )~$
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return n; vT@*o=I
} qlSI|@CO
}aO6%
WbJ|]}hJ\
} ]gjQy.c|
)XCG4-1
mR,w~wP
/* P* X^)R
**SiteInfoBean.java d*$L$1S
*/ K@%o$S?>z_
package NetFox; :1asY:)vNP
Me 5Xd|
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public class SiteInfoBean { ej91)3AO
OQ(w]G0LP
gn//]|#H+
private String sSiteURL; //Site's URL Es<& 6
private String sFilePath; //Saved File's Path *kYJwO^
private String sFileName; //Saved File's Name 8k{KnH
private int nSplitter; //Count of Splited Downloading File N\l|3~
Mmmg3%G1
>\br8=R
public SiteInfoBean() -7Bg5{FA
{//nSplitter的缺省值为5 pO?v$Rjl
//default value of nSplitter is 5 bv^wE,+?o
this("","","",5); =jEVHIYt
} knn9s0'Q
VLPPEV-u
g^l~AR
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) k"3@G?JY
{ 0Q7|2{
sSiteURL= sURL; |LV}kG(2
sFilePath = sPath; ~6A;H$dr
sFileName = sName; _u3%16,o
this.nSplitter = nSpiltter; &w!(.uDO
R$h B9BK
%i6/= 'u
} ++sbSl)Q
buldA5*!o
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public String getSSiteURL() '4Drs}j5
{ oeYUsnsbi
return sSiteURL; A^c (
} }y1r yeW<
z"nMR_TTu
::p%R@?
public void setSSiteURL(String value) s !IvUc7'
{ :}UjX|D
sSiteURL = value; ,|g&v/WlC%
} <a&w$Zc/
tmd{Gx}c
u4tv=+jh
public String getSFilePath() x4i&;SP0
{ y@@h)P#
return sFilePath; +[ng99p
} m*wDJEKo
B)*1[Jf{4
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public void setSFilePath(String value) U2)?[C1q{
{ Dz,|sHCmk
sFilePath = value; 'rNLh3
} )<%CI#s#
]SAGh|+xl
4p7j"d5
public String getSFileName() )(OGo`4Qz
{ 1pK(tm
return sFileName; DS+BX`i%#p
} n/Dg)n?
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z6Fl$FFP
public void setSFileName(String value) ay =B<|!
{ 1+"d-`'Z2O
sFileName = value; X(O:y^sX}
} ]4/C19Fe!
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public int getNSplitter() ly69:TR7I
{ 1,:QrhC
return nSplitter; fRxn,HyV
} >7)QdaB
V["'eJA,,
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public void setNSplitter(int nCount) \PD%=~
{ #]QS
nSplitter = nCount; s1R#X~d
} :L6%57
} bxPJ5oT
A#{I-*D[
k%8kt4\wn6
/* AQtOTT$
**Utility.java y<*\D_J
*/ LN)yQ-
package NetFox; nltOX@P-
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%__ @G_M
public class Utility { Y O|hwhe_
G({5LjgW
W9{;HGWS
public Utility() ^Y!$WP
{ ;1s;"
N A_8<B^
bl^pMt1fv
} EiP N44(
C8i4z
//线程睡眠 ,<C~DSAyZ
public static void sleep(int nSecond) rLY I\
{ 3''Uxlo\
try{ \acGSW .c
Thread.sleep(nSecond); ,-kz\N@.
} fB&i{_J
catch(Exception e) t'yh&44_
{ ?=1i:h
e.printStackTrace (); s'd\"WaQV
} [S-#}C?~
} QxuU3#l
6(7dr?^eGT
//日志 RQu[FZT,
public static void log(String sMsg) T!pA$eE
{ zGc]*R
System.err.println(sMsg); R7;X
} aI|X~b
a[,p1}!_
2f{a||
public static void log(int sMsg) (WP^}V5
{ *5\'$;Rg
System.err.println(sMsg); ,1.Td=lY$
} |eFaOL|
} +.rE|)BPy
loHMQKy@
eht>4)
/* &T ^bv*P
**TestMethod.java \IEuu^
*/ V}~',o<m
package NetFox; kY9$ M8b
#;+SAoN
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public class TestMethod { 9l|*E
)>iPx.hVSS
'geN dx
public TestMethod() -a"b:Q
{ ///xx/weblogic60b2_win.exe <xrya_R?
try{ [@3.dd
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); W59xe&l
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \.GA"_y
SiteFileFetch fileFetch = new SiteFileFetch(bean); 8wEJyAu2
fileFetch.start(); ?(}~[
} \C2HeA\#SW
catch(Exception e){e.printStackTrace ();} ttt4h
/)dyAX(
A6E~GJa
} H;DjM;be
}I#_H
9[ o$/x}
public static void main(String[] args) cFq2 6(e
{ .ezZ+@LI+#
new TestMethod(); 10GU2a$0"$
} ICc:k%wE7
} {h.j6
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