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)); dHf_&X2A
} rS(693kb
for(int i=0;i<nEndPos.length-1;i++) 8EbYk2j
{ `j4ukOnG
nEndPos = nStartPos[i+1]; C&<f YCwG
} i1 SP
nEndPos[nEndPos.length-1] = nFileLength; ?$-OdABXHK
} u4z]6?,"e
} HOykmx6$
6prN,*k5
2',t@<U
//启动子线程 G-M!I`P
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {l *ps-fi
for(int i=0;i<nStartPos.length;i++) ^>g+:?x
{ y<)Lr}gP
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), K Qub%`n
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), a5Xr"-
nStartPos,nEndPos,i); &z1r$X.AW
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !c(B^E
fileSplitterFetch.start(); 7:M%w'oR
} bhe|q`1,E
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), I \vu?$w
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 6G@_!i*2F
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", "-ZuH
nEndPos = " + nFileLength); v`y{l>r,
// fileSplitterFetch[nPos.length-1].start(); l4;/[Q>Z
{hg,F?p '
_e~EQ[,
//等待子线程结束 'f;+*~*L
//int count = 0; wF@qBDxg
//是否结束while循环 x0Tb7y`
boolean breakWhile = false; iKp4@6an
bG.aV#$FIg
N1#*~/sXh
while(!bStop) $D9JsUij
{ F P mLost
write_nPos(); 20%xD e
Utility.sleep(500); Gtg;6&2
breakWhile = true; er l_Gg
:Q?xNY%
& r\z9!
for(int i=0;i<nStartPos.length;i++) \zj8| +
{ TO( =4;U
if(!fileSplitterFetch.bDownOver) qMI%=@=
{ J#:%| F%
breakWhile = false; x:sTE u@
break; z${B|
} .]v8W51Y
} lpSM p
if(breakWhile) <FGNV+?%e
break; +Icg;m{
^BNg^V.
L2Gm0 v
//count++; @#8F5G#
//if(count>4) =H!u4
// siteStop(); LAMTf"a
} }p8a'3@Z
(U$ F) 7
g~10K^
System.err.println("文件下载结束！"); *QAK9mc
} Z[0xqGYLB
catch(Exception e){e.printStackTrace ();} evimnV
} mKxQU0`
!y4o^Su[
-fG;`N5U
//获得文件长度 O$#`he/jm
public long getFileSize() ajkRL|^
{ ~5cLI;4h
int nFileLength = -1; =C<_rBY
try{ tgg*6lc
URL url = new URL(siteInfoBean.getSSiteURL()); {:{NK%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); AO8`ItNZdT
httpConnection.setRequestProperty("User-Agent","NetFox"); JRU)AMMU&
tOp>OoD
B[cZEFo\
int responseCode=httpConnection.getResponseCode(); 61!R-
if(responseCode>=400) G.T}^xHmL
{ 0%'&s)#
processErrorCode(responseCode); A5?[j QT0
return -2; //-2 represent access is error nW{7L
} GW`9SB
Sfh\4h$H
SC86+
String sHeader; \J9@p
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#W!@j"8eK
for(int i=1;;i++) SBeb}LZ
{ 8LR_K]\
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Qy@chN{eP
//Utility.log(in.readLine()); AX]lMe
sHeader=httpConnection.getHeaderFieldKey(i); wm8(Ju
if(sHeader!=null) ~p8-#A)X,)
{ +XFF@h&=t
if(sHeader.equals("Content-Length")) &IOChQ`8P
{ :[\}Hn=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 7CM<"pV
break; Q> @0'y=s
} Et`z7Q*e
} }@a_x,O/x}
else in#g
break; =3/||b4c
} *PZNZ{|m
} ` [@ F3x
catch(IOException e){e.printStackTrace ();} ur*1I/v
catch(Exception e){e.printStackTrace ();} d;;]+%
_j<46^
#Du1(R
Utility.log(nFileLength); $Wb"X=}tl
cq@8!Eu w]
8n);NZ
return nFileLength; IY,&/MCh
} KcNEB_i
\gj@O5rGP
&m+s5
//保存下载信息（文件指针位置） s?E7tmaM
private void write_nPos() !cp ,OrO\
{ -br/
try{ e[w)U{|40
output = new DataOutputStream(new FileOutputStream(tmpFile)); ]#R;%L
output.writeInt(nStartPos.length); 'iUfr@
for(int i=0;i<nStartPos.length;i++) ,Iwri\
{ ]|~],\
// output.writeLong(nPos); VEo>uR
output.writeLong(fileSplitterFetch.nStartPos); jIAl7aoY
output.writeLong(fileSplitterFetch.nEndPos); ZqS'xN:k
} s{`r$:!
output.close(); 2-]gHAw%
} 8cR4@Hqx
catch(IOException e){e.printStackTrace ();} 0=L:8&m
catch(Exception e){e.printStackTrace ();} l"b78n
} IqcPml{\
.CrahV1G
:m^eNS6:
//读取保存的下载信息（文件指针位置） a|TP2m
private void read_nPos() A&F@+X6@
{ +anNpy
try{ I)Lg=n$
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 9[6xo!
int nCount = input.readInt(); i&{8a3B
nStartPos = new long[nCount]; *sZOws<
nEndPos = new long[nCount]; Ok2k; +l
for(int i=0;i<nStartPos.length;i++) mcp}F|ws
{ aq,&W q@
nStartPos = input.readLong(); <iJ->$
nEndPos = input.readLong(); 6-QTqb?U;N
} 1th|n
input.close(); >Y)jt*vQ
} FU5vo
catch(IOException e){e.printStackTrace ();} mi%d([)%<
catch(Exception e){e.printStackTrace ();} YNHn# 98\
} &Q(Q/]U~
w*$nG$
sqj8c)6
private void processErrorCode(int nErrorCode) )uZ<?bkQ
{ T3%yV*F,
System.err.println("Error Code : " + nErrorCode); ?Z*LTsPr
} 2syKYHV
Ny p5=
;:8_H0X'K
//停止文件下载 o&fAnpia=
public void siteStop() 76mQ$ze
{ ^e<0-uM"s
bStop = true; WLv( K_3Y
for(int i=0;i<nStartPos.length;i++) byyz\>yAVq
fileSplitterFetch.splitterStop(); FyQ
IEjKI"
n=L;(jp<j
} +cQ4u4
} "xdXHuX
//负责部分文件的抓取 >77 /e@
**FileSplitterFetch.java [[oX$0Fp\!
*/ WTSY:kvcCY
package NetFox; G@ BrU q
l3b$b%0'
z#8GF^U:T
import java.io.*; tJbOn$]2"
import java.net.*; .kBi" p&
hTf]t
@,pO%,E6
public class FileSplitterFetch extends Thread { l4|bpR Cp
b ]1SuL
_I3j7f,V
String sURL; //File URL dkLc"$(O
long nStartPos; //File Snippet Start Position *N[.']#n
long nEndPos; //File Snippet End Position \,ir]e,1
int nThreadID; //Thread's ID Y>wpla[kUq
boolean bDownOver = false; //Downing is over o5i?|HJ
boolean bStop = false; //Stop identical ShF ][v1L
FileAccessI fileAccessI = null; //File Access interface vA;ml$
ZRsDn
$9M>B<]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException 8/ZJkI
{ LN" bGe
this.sURL = sURL; Bx j6/a7Xd
this.nStartPos = nStart; oT5?*3f
this.nEndPos = nEnd; aq0J }4U
nThreadID = id; )}]<o |'
fileAccessI = new FileAccessI(sName,nStartPos);//定位 no)Spo'
} c{V0]A9VF
+\\*Iy'xK
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public void run() ()}O|JL:K
{ xJJlVP
while(nStartPos < nEndPos && !bStop) y? )v-YGu
{ mQ('X~l
t`Mm
TB*g$*
try{ )PB&w%J
URL url = new URL(sURL); {KdC51"Nv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); QE=Cum
httpConnection.setRequestProperty("User-Agent","NetFox"); *{)[:;
String sProperty = "bytes="+nStartPos+"-"; !|}J{
httpConnection.setRequestProperty("RANGE",sProperty); A5F< <
Utility.log(sProperty); lWd)(9Kj
V[rNJf1z
DTlM}
InputStream input = httpConnection.getInputStream(); L7wl3zG
//logResponseHead(httpConnection); =LZj6'
$_@~t$
aVO5zR./)
byte[] b = new byte[1024]; 0A9x9l9Wd
int nRead; "n7rbh3VW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) xAjLn*d|N
{ vObP(@0AM
nStartPos += fileAccessI.write(b,0,nRead); ^qIp+[/'
//if(nThreadID == 1) Op~sR^ez
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); x,5$VLs\+
} o3]B/
&&M-5XD
>O9j},X
Utility.log("Thread " + nThreadID + " is over!"); jf$6{zO6j
bDownOver = true; X>wB=z5PXK
//nPos = fileAccessI.write (b,0,nRead); slDxsb
} /49PF:$?
catch(Exception e){e.printStackTrace ();} r*0a43mC1
} /FkLZm
} (|bMtT?"x
}rn}r4_a
Kbg`ZO*
//打印回应的头信息 aVz<RS
public void logResponseHead(HttpURLConnection con) w4:n(.;HK
{ HP3~.1Sp
for(int i=1;;i++) Olj]A]v}
{ N#bWMZ"
String header=con.getHeaderFieldKey(i); (=QaAn,,R
if(header!=null) ie 2X.#
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5w@ ;B
Utility.log(header+" : "+con.getHeaderField(header)); DcQ^V4_
else oZA|IF8U0
break; A0V"5syY
} _B8e1an
} 2t< dCw
f"k?Ix\ e
lqF{Y<l
public void splitterStop() $P866F
{ 7B"J x^
bStop = true; 0`h[|FYV
} KQJn\#>
{l0;G)-
rPaD#GA[7
} 69dFd!G\
[{}9"zB$x0
h|!B;D
/* f8#WT$Ewy
**FileAccess.java 6!n"E@Bwu
*//文件访问(定位，写) SR*%-JbA
package NetFox; vk5pnCM^3
import java.io.*; Ua5m2&U1
T!"<Kv]J
n{r+t=X
public class FileAccessI implements Serializable{ %,K|v
V~Tjz%<
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 :0CR=]WM
RandomAccessFile oSavedFile; R`76Ae`R8
long nPos; d;mQ=k 1
p? iJ'K
j72cSRv
public FileAccessI() throws IOException ;wL*
{ U"%k4]:A
this("",0); ~9kvC&/{[
} SjtGU47$!
Rb#Z'1D'G
6KnD(im
public FileAccessI(String sName,long nPos) throws IOException Ook3B
{ 9`4h"9dO
oSavedFile = new RandomAccessFile(sName,"rw"); ,\+tvrR4X
this.nPos = nPos; Gxi;h=J2)>
oSavedFile.seek(nPos); x3PeU_9
} ii2oWU
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fOE:~3Q
public synchronized int write(byte[] b,int nStart,int nLen) i#kRVua/
{ c*RZbE9k
int n = -1; K[~Wj8W0
try{ o4w+)hh
oSavedFile.write(b,nStart,nLen); Qc[[@=S%
n = nLen; Yo| H`m,
} mH;Z_ME"
catch(IOException e) u8+<uWB
{ >z>UtT:
e.printStackTrace (); $rFv(Qc^=
} ~q4DePVE
kgr:85
_q6+]
return n; `Jm{K*&8Q
} oxO}m7ULH
oq8~PTw
e!tgWYN
} <'P|g
1G.+)*:3
aCGPtA'
/* _9!Ru!u~
**SiteInfoBean.java k_P`t[YZV
*/ T2Y`q'
package NetFox; PO&xi9_
`c:'il?
7c %@2
public class SiteInfoBean { VZAdc*X
OUI}jJw+
ry~3YYEMI0
private String sSiteURL; //Site's URL M#<x2ojW
private String sFilePath; //Saved File's Path Z"Et]xSU%$
private String sFileName; //Saved File's Name Sw5H+!
private int nSplitter; //Count of Splited Downloading File /R|"/B0
_& KaI }O
R)<Fqa7Tm
public SiteInfoBean() !~ -^s
{//nSplitter的缺省值为5 d57(#)`
//default value of nSplitter is 5 mG?a)P
this("","","",5); KOi%zE%
} {dMa&r|lp
f\r$T Nd6
HoRLy*nU
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 2mU}"gf[
{ _xUhDu%
sSiteURL= sURL; (/k,q
sFilePath = sPath; (]7@0d88
sFileName = sName; ,P auP~L
this.nSplitter = nSpiltter; NA/+bgyuT>
* +OAc`8
Bj@&c>
} }Ecm
l\$C)q6O
QRdb~f;<hj
public String getSSiteURL() n8:2Z>
{ .-RWlUe;,
return sSiteURL; q8kt_&Ij
} "hy#L 0\t
"H G:by
R`1$z8$
public void setSSiteURL(String value) zR{TWk]
{ gvcT_'
sSiteURL = value; f^$\+H"W
} 4a!L/m*
jU4Ir{f
zcxG%? Q
public String getSFilePath() OVj,qL)
{ 8De `.!Gg
return sFilePath; o,aI<5"
} e;!<3b
NoKYHN^*w
i^QcW!X&
public void setSFilePath(String value) =A!I-@]q<
{ 57[O)5u.+
sFilePath = value; JRodYXjE
} l
\[>Rt
{|rwIRe
public String getSFileName() IL>g-
{ Wq,UxMz
return sFileName; *-P@|eg
} NEGpf[$
4tu2%Og)?
>Zr/U!W*?
public void setSFileName(String value) \{UiGCK
{ l;|1C[V
sFileName = value; 0j_!)B
} JT_#>',
P AKh v.7
}>0UaK
public int getNSplitter() x`o_&09;CG
{ hOwVm;:
return nSplitter; [6/%ynlP
} F[?t"d
7 'f>
D2?7=5DgS
public void setNSplitter(int nCount) P,>#
{ Q0 ^?jh
nSplitter = nCount; A$5!]+
} -7pZRnv
} .d8~]@U!<
}RyYzm2
|UlScUI,
/* (TY^ kySr
**Utility.java ](a<b@p
*/ I`y}Ky<q
package NetFox; FijzO
] xH `
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public class Utility { SgY>$gP9S
JgxOxZS`@
IGbQ L
public Utility() J7l1-
{ ZM)a4h,kcm
0#yo\McZ
Y)a 7osML
} @|cas|U.r
a]ftE\99
//线程睡眠 Y)!5Z.K
public static void sleep(int nSecond) "C0oFRk
{ -bs~{
try{ xUeLX`73
Thread.sleep(nSecond); F-ijGGL#
} A!j&g(Z"Q
catch(Exception e) (^6SF>'
{ i4uUvZf
e.printStackTrace (); IB?5y~+h
} 9pk<=F
} Z&21gN
+1cK (Si
//日志 $)\ocsO
public static void log(String sMsg) -Ol/r=/&
{ TSD7.t)^
System.err.println(sMsg); 2?m'Dy'JE
} NDI|;
,ur_n7+LH
&PGU%"rN
public static void log(int sMsg) g.,IQ4o
{ ,7/N=mz
System.err.println(sMsg); M/#<=XhA
} 5X[=Q>
} WO '33Q(
~s88JLw%&u
H(""So7L
/* ,rG$JCS'KQ
**TestMethod.java (A?e}M^}
*/ T$RZRZo
package NetFox; u/``*=Y@
hB|LW^@v
5$jKw\FF=
public class TestMethod { O@EpRg1
% +eZ U)N
cl{;%4$9
public TestMethod() }b~ZpUL!
{ ///xx/weblogic60b2_win.exe =m1B1St2
try{ >-]Y%O;}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); y&SueU=
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); \E0Uj>9+[
SiteFileFetch fileFetch = new SiteFileFetch(bean); B'&%EW]
fileFetch.start(); CjykM])
} 1'}~;?_
catch(Exception e){e.printStackTrace ();} d7l0;yR&+
jMZ{>l.v
4Kx;F 9!%~
} wLNO\JP'
!v94FkS>
b^FB[tZ\x
public static void main(String[] args) RELLQpz3
{ CxwZ$0
new TestMethod(); +e4o~p
} S^~GI$
} >D*L0snjV
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