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)); q+>J'UGb
} %=xR$<D
for(int i=0;i<nEndPos.length-1;i++) o$FqMRep
{ )q&=x2`
nEndPos = nStartPos[i+1]; s?@{
} g7res
nEndPos[nEndPos.length-1] = nFileLength; RY2`v pv
} E)DdiB'Rh
} zRbooo{N
JV=d!Gi[C
^a4y+!
//启动子线程 //2G5F;
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; -x=abyD
for(int i=0;i<nStartPos.length;i++) S0eD 2
{ 6UXa 5t
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (Hb i+IHV
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 8zS't2 u
nStartPos,nEndPos,i); AdxCP\S&
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); O;h]
fileSplitterFetch.start(); (9]`3^_,J
} ,R5NKWo
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 3P-qLbJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); h7c8K)ntnf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", X3vTyIsn
nEndPos = " + nFileLength); uvz}qH@j/Q
// fileSplitterFetch[nPos.length-1].start(); V'sp6:3*\
??5qR8n.
g^OU+7o
//等待子线程结束 8aQ\Yx
//int count = 0; B<i)je!
//是否结束while循环 a1R2ocC
boolean breakWhile = false; AmNmhcN
[8l;X:
9!zUv:;
while(!bStop) 2siUpmX
{ Gnop
write_nPos(); !:PF |dZ
Utility.sleep(500); FVNxjMm,
breakWhile = true; R| [mp%Q
Y[k%<f
4vq,W_n.hQ
for(int i=0;i<nStartPos.length;i++) xwhH_[
{ 2qLRcA=R
if(!fileSplitterFetch.bDownOver) SV}q8z\
{ p(in.Xz
breakWhile = false; 9oKRnc
break; JG @bl
} rT9<_<
} uUu]JDdz
if(breakWhile) ?W-J2tgss{
break; [0U!Y/?6lA
;A7HEx
Ymkk"y.w
//count++; 5<\&7P3y
//if(count>4) Y0fX\6=h
// siteStop(); xZZW*d_b
} Is&z~Xy/
]S4TX
{Tb(4or?=b
System.err.println("文件下载结束！"); ,TPNsz|Q
} s1.YH?A;
catch(Exception e){e.printStackTrace ();} `W,gYH7
} 6AV@O
KoVy,@
]BGWJA5
//获得文件长度 8mI eW
public long getFileSize() NPc]/n?vDj
{ L)H'g
int nFileLength = -1; -L>xVF-|:1
try{ hn\<'|n
URL url = new URL(siteInfoBean.getSSiteURL()); pv*u[ffi
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o?@,f/"5
httpConnection.setRequestProperty("User-Agent","NetFox"); ~?4'{Hc'
l&2A]5C
5RCQ<1
int responseCode=httpConnection.getResponseCode(); c'B6E1}sx
if(responseCode>=400) v1%rlP
{ )X2=x^u*U
processErrorCode(responseCode); u~FXO[b
return -2; //-2 represent access is error jH#Tt;
} ykcW>h
6!7LgM%4
}w .[ZeP
String sHeader; d~@&*1}
-jy-KC
.^j6
for(int i=1;;i++) X-&t!0O4}`
{ # le<R
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); b-R!oP+vP
//Utility.log(in.readLine()); g((glr)6M
sHeader=httpConnection.getHeaderFieldKey(i); M&o@~z0
if(sHeader!=null) fQ c%a1'
{ MUsF/1
if(sHeader.equals("Content-Length")) I:l<t*
{ p.^glz>B
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); *X- 6]C
break; 0Ou;MU*v
} H1X38
} K0$8t%Z.
else ; mnV)8:F
break; ^Uss?)jN4
} 17g\XC@ Cl
} tj/X7|
catch(IOException e){e.printStackTrace ();} aC:Sy^Tf
catch(Exception e){e.printStackTrace ();} 5q?2?j/h
D#|+PG7
$/^DY&
Utility.log(nFileLength); ~?i;~S
7pH`"$
(8DJf"}
return nFileLength; ZYDLl8
} a_Y*pOu
dU%Q=r8R
?oF+?l
//保存下载信息（文件指针位置） EfHo1Yn&
private void write_nPos() SXkUtY$
{ 1vKc>+9
try{ (n:d {bKV
output = new DataOutputStream(new FileOutputStream(tmpFile)); _Kdqa%L !
output.writeInt(nStartPos.length); :L gFd
for(int i=0;i<nStartPos.length;i++) 1xN6V-qk
{ z%-Yz-G9
// output.writeLong(nPos); iIWz\FM
output.writeLong(fileSplitterFetch.nStartPos); 5|S|S))_Q
output.writeLong(fileSplitterFetch.nEndPos); Pqiw[+a$
} &|>CW:)&1"
output.close(); .%)FK#s-
} ;Q"xXT`;:
catch(IOException e){e.printStackTrace ();} Ay\=&4dv
catch(Exception e){e.printStackTrace ();} eX7dyM
} ~/Gx~P]
=kvfe" N0e
eF+:w:\h
//读取保存的下载信息（文件指针位置） g-`HKoKe
private void read_nPos() C "XvspJ
{ G|eY$5!i
try{ rMRM*`Q2
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ^<X+t&!z
int nCount = input.readInt(); N~7xj?
nStartPos = new long[nCount]; !$&k@#v:
nEndPos = new long[nCount]; K=,nX7Z5
for(int i=0;i<nStartPos.length;i++) 'z$BgXh\
{ u[nx?!
nStartPos = input.readLong(); xCU^4DO3p
nEndPos = input.readLong(); q =sEtH=
} ":s1}A
input.close(); al>^}:
} RsV<4$
catch(IOException e){e.printStackTrace ();} A9Cq(L_H
catch(Exception e){e.printStackTrace ();} rg Gm[SL*<
} m(MPVY<X
?sfas57&y
`o~dQb/k+
private void processErrorCode(int nErrorCode) iSDE6
{ | RMIV
System.err.println("Error Code : " + nErrorCode); Py2AnpYa
} 7|4t;F!
]7<}EG
e8T#ZWr*
//停止文件下载 o!:V=F
public void siteStop() >YP6/w,e
{ I(LBc
bStop = true; h| q!Qsnj'
for(int i=0;i<nStartPos.length;i++) w`_cmI
fileSplitterFetch.splitterStop(); K_/-mwA v
P$LHsg]
o,o,(sII
} 9G njJ
} hP1}Do
//负责部分文件的抓取 1aEM&=h_W
**FileSplitterFetch.java *sNZ.Y:.
*/ yB][ 3?lv
package NetFox; [:M:6JJ
P<<?7_ ??
M"QT(u+
import java.io.*; &!/E&e$_
import java.net.*; "rhU2jT=c
A4;EtW+F
z&fXxp
public class FileSplitterFetch extends Thread { qm RdO R
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I*,!zym
String sURL; //File URL tBR"sBiws
long nStartPos; //File Snippet Start Position j1/.3\
long nEndPos; //File Snippet End Position 80qSPitj
int nThreadID; //Thread's ID yX%q7ex
boolean bDownOver = false; //Downing is over )_[eqr
boolean bStop = false; //Stop identical >K]s)VuWR
FileAccessI fileAccessI = null; //File Access interface 'Xj9sAB
&f12Q&jY7
w-f[h
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 5/U|oZM"
{ {NmpTb
this.sURL = sURL; uZ[7[mK}n7
this.nStartPos = nStart; P .I<.e
this.nEndPos = nEnd; lw/zgR#|
nThreadID = id; ,-!h
fileAccessI = new FileAccessI(sName,nStartPos);//定位 yb 7
} &.dC%
&8kc0Z@y
61qs`N=k
public void run() i%~^3/K
{ )=,%iL-
while(nStartPos < nEndPos && !bStop) h7],/? s
{ .KzGb4U
Af*e:}}
=E{e|(1+u
try{ 6yDc4AX
URL url = new URL(sURL); pwj?
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w5j6RQml
httpConnection.setRequestProperty("User-Agent","NetFox"); *g0}pD;r
String sProperty = "bytes="+nStartPos+"-"; %V40I{1
httpConnection.setRequestProperty("RANGE",sProperty); g&z)y
Utility.log(sProperty); Z0o+&3a6
7Jm&z/
<i~O0f]
InputStream input = httpConnection.getInputStream(); OnD!*jy
//logResponseHead(httpConnection); (_:k s
9VqE:c /
N(*Xjy+PX
byte[] b = new byte[1024]; N0Y$QWr_$
int nRead; XctSw
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) . X(^E
{ ].E89_|O
nStartPos += fileAccessI.write(b,0,nRead); jZRf{
//if(nThreadID == 1) FG-v71!h#
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); q_0So}
} ;3\oU$'
E;$;g#ksf
BQX6Q<
Utility.log("Thread " + nThreadID + " is over!"); nIRJ5|G(
bDownOver = true; rE:"8d}z
//nPos = fileAccessI.write (b,0,nRead); h$F.(NIYe
} )Dg;W6
catch(Exception e){e.printStackTrace ();} .Vohd@s9l
} "nkj_pC
} 0Dx,)C
(#|CL/&
f9+J}
//打印回应的头信息 G~$.Af!9W
public void logResponseHead(HttpURLConnection con) $P=B66t ^
{ + F{hFuHV
for(int i=1;;i++) D'{NEk@
{ v|\<N!g
String header=con.getHeaderFieldKey(i); (lNV\Za
if(header!=null) B=EI&+F+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); |rjHH<
Utility.log(header+" : "+con.getHeaderField(header)); IJWUNKqo=
else H2f!c{t$p
break; =[N=mC
} x,CTB
} 79DzrLu
%kS4v,I
=rw60B
public void splitterStop() E_fH,YJ?9
{ |E%i t?3M
bStop = true; ~0;l\^
} Yf=an`"
4trP*u,4
Ry$zF~[
} \a_75^2
e(e_p#
gdPPk=LD
/* [uJfmrEH
**FileAccess.java 6MewQ{hi
*//文件访问(定位，写) {;z{U;j
package NetFox; JJIlR{WY_
import java.io.*; -<g&U*/E
i6S5 4&^!
{Xw6]d
public class FileAccessI implements Serializable{ {D6p?TL+
9.:]eL
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 fwkklg^
RandomAccessFile oSavedFile; & bKl(,
long nPos; 3"*tP+H
fbTq?4&Q
)S:,q3gxJ
public FileAccessI() throws IOException eD(;Wn
{ 65%WjO
this("",0); lx'^vK%F
} }@)r\t4m
Li'>pQ+
Z<yLu'48)A
public FileAccessI(String sName,long nPos) throws IOException %>z4hH,
{ %9q]
oSavedFile = new RandomAccessFile(sName,"rw"); F K7cDaI
this.nPos = nPos; BR*'SF\T
oSavedFile.seek(nPos); K@f@vyw]
} ifXGH>C
EZ"n3#/
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public synchronized int write(byte[] b,int nStart,int nLen) 65HP9`5Tm
{ Z!/!4(Fh
int n = -1; Q!91uNL
try{ v)f;dq^z-
oSavedFile.write(b,nStart,nLen); Jbv[Ql#
n = nLen; 1*aO2dOq
} B~CdY}UTsj
catch(IOException e) & t.G4
{ 5[[mS
e.printStackTrace (); ]ZMFK>"^%
} RXi/&'+H
)Ja&Y
?rJe"TOIy
return n; 8t)?$j$
} @TQzF-%#7
o]@Mg5(8Q
Q)IL]S
} I[l8@!0
f}!Eu
Uhw:XV@m
/* f`gs/R
**SiteInfoBean.java qk{+Y
*/ @W1F4HYds
package NetFox; 2Y7u M;8
N|rB~
baO'FyCs9&
public class SiteInfoBean { 9cnLf#
yrF"`/zv6|
G%HuB5:u
private String sSiteURL; //Site's URL ^H(,^cVN
private String sFilePath; //Saved File's Path ^vY[d]R _\
private String sFileName; //Saved File's Name +%~/~1
private int nSplitter; //Count of Splited Downloading File q:/3uC7
^[6S]Ft(
SWLt5dV
public SiteInfoBean() 6IPQ}/l
{//nSplitter的缺省值为5 (a9>gLI0
//default value of nSplitter is 5 A<U9$"j9J
this("","","",5); F1q6 3
} Mb^E
,J4rKGG
W\pO`FL
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) m<e_Z~^G
{ ~PtIq.BY
sSiteURL= sURL; CX}==0od
sFilePath = sPath; $<s;YhM:u)
sFileName = sName; JQ%D6b
this.nSplitter = nSpiltter; 7C>5XyyJ
L)z`
1EemVZdY
} +B&,$ceyaJ
'* eeup
b6?&h:{k
public String getSSiteURL() 1PUeU+
{ i",7<01
return sSiteURL; 8W2oGL6
} /wX5>^
Rn_FYP
BW x=Q
public void setSSiteURL(String value) TY`t3
{ E;bv;RUio
sSiteURL = value; u Wxl\+_i
} =v{Vl5&>?
,<t)aZL,A;
Tl!}Rw~Pg
public String getSFilePath() o JX4+uJ
{ UGP,/[XI
return sFilePath; aCF=Og
} g2%fla7r
>]<4t06D
H7{I[>:
public void setSFilePath(String value) gLK_b;:
{ ?J,K[.z
sFilePath = value; oe*CZ
} P[%nD cB
REGk2t.L
sXwa`_{
public String getSFileName() F#)@ c
{ E<[Y KY
return sFileName; fZavZ\qU
} P47x-;
eXAJ%^iD
dqgH"g
public void setSFileName(String value) 6FkBb!ASk
{ #SX-Y)> 1@
sFileName = value; ez14f$cJ+
} mMw--Gc?
ECk* H
)dfwYS*[n
public int getNSplitter() e0ULr!p
{ Z</57w#-7
return nSplitter; wE3fKG.
} 5ENEx
~X<?&;6
FWW*f _L
public void setNSplitter(int nCount) \IP 9EFA
{ PY MofQaZ
nSplitter = nCount; ;~GBD]
} 1<;VD0XX
} slQEAqG)B
UuCRQNH
2QgD<
/* oc"7|YG
**Utility.java \DcO.`L
*/ J,*+Ak ~
package NetFox; hrW2#v
8 .t3`FGH
Vt(s4
public class Utility { `>&K=C?
8`z
DJb9] ,=a
public Utility() # TZ`
{ o]DYS,v
DN;|?oNZ
]Q#k"Je
} gKP=@v%-
8GeJ%^0o}
//线程睡眠 7$mB.\|
public static void sleep(int nSecond) 6x;!E&<
{ [P`<y#J3F
try{ zvn3i5z
Thread.sleep(nSecond); <+Gf!0i
} jJD*s/o
catch(Exception e) iu.Jp92
{ !j/54,
e.printStackTrace (); -TS5g1
} >P ~j@Lv
} P)O:lYX
^Rh}[
//日志 *!9=?
public static void log(String sMsg) L=dQ,yA
{ F#^/=AR'
System.err.println(sMsg); 7c!#e=W@B
} owx0J,,G
mFmxEv
tL M@o|:
public static void log(int sMsg) gwbV$[.X
{ Z*'<9l_1
System.err.println(sMsg); 2U3e!V
} eV"s5X[$
} (}rBnD
HWFLu
s Fx0
/* 9)>+r6t
**TestMethod.java n~ZZX={a
*/ <}G/x*N
package NetFox; rv c%[HfW;
1DlXsup&?#
=7[}:haB{
public class TestMethod { &Im-@rV!
)J?8"+_Y
]X> I(p@
public TestMethod() BO2s(8
{ ///xx/weblogic60b2_win.exe R$`%<Y3)
try{ KA>QW[HX
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &eb8k2S
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $/ g<h
SiteFileFetch fileFetch = new SiteFileFetch(bean); {Wndp%
fileFetch.start(); k2(k0HFR
} h.wffk,
catch(Exception e){e.printStackTrace ();} 'e_e*.z3
4dy!2KZN
P`avn
} -f*5lkO
|;\pAZ2
y&/bp<Z
public static void main(String[] args) RXw1HRR$V
{ 1bjz :^
new TestMethod(); CF:L#r
} S f6%A
} !<out4Mz"
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