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)); ~T7\lJ{%G
} S=!3t`
for(int i=0;i<nEndPos.length-1;i++) {<5rbsqk
{ \/I@&$"F
nEndPos = nStartPos[i+1]; /Li?;H
} u~=>$oT't
nEndPos[nEndPos.length-1] = nFileLength; /v7U~i5
} qd6XKl\5
} '9>z4G*Td
xV @X%E
{wiw]@c8
//启动子线程 f'Dl*d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; v?F~fRH
for(int i=0;i<nStartPos.length;i++) 6H\3
{ id8a#&t]
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), nyD(G=Q5
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), BY.'0,H=k
nStartPos,nEndPos,i); #lRkp.e
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); )=V0
fileSplitterFetch.start(); %,Xs[[?i
} N%'=el4L
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), *aT3L#0(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 'z0@|a
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", LRW7_XYz
nEndPos = " + nFileLength); (?Fz{
// fileSplitterFetch[nPos.length-1].start(); yxh8sAZ
Z.Z+cFi
R_eKKi@VH
//等待子线程结束 l 3bo
//int count = 0; BFc=GiPnQ
//是否结束while循环 c7.%Bn,
boolean breakWhile = false; rwGY)9|
73OFFKbsk
8Ih+^Y a
while(!bStop) 3yn>9qt
{ N1`/~Gi
write_nPos(); HWG5Ghu8,)
Utility.sleep(500); )<-\ F%&b
breakWhile = true; k;/U6,LQ*
@JVax-N
ZNNgi@6>
for(int i=0;i<nStartPos.length;i++) N '2Nv
{ pwU l&hwte
if(!fileSplitterFetch.bDownOver) fx2r\ usX[
{ : &>PN,q>
breakWhile = false; zBV7b| j
break; A q;]al
} ORHs1/L`j
} yPL1(i;
if(breakWhile) DS0c0lsx
break; JJ[.K*dO
Hz&a~
wK0vKdi
//count++; *U|K~dl]K
//if(count>4) q'9u8b
// siteStop(); .I_Mmaq;i
} *P]FX-D3
|{]W (/
i;>Yx#
System.err.println("文件下载结束！"); U<QO@5
} U0G(
catch(Exception e){e.printStackTrace ();} (+lwt
} qKag'0e
>J,Rx!fq3
")LcB'C
//获得文件长度 + pTc2z
public long getFileSize() [Zc8tE2oN
{ U[1Rw6
int nFileLength = -1; Ze_4MwCW
try{ N# $ob9
URL url = new URL(siteInfoBean.getSSiteURL()); &g%9$*gmT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;DbEP.%u$
httpConnection.setRequestProperty("User-Agent","NetFox"); H=O/w3
+Z99x#
da<B6!
int responseCode=httpConnection.getResponseCode(); @."_XL74
if(responseCode>=400) PoTJ4z
{ 6wK>SW)#&j
processErrorCode(responseCode); mDZ/Kp{
return -2; //-2 represent access is error L,6v!9@
} eK[8$1
`5,46_
I~ Q2jg2
String sHeader; ?T]3I.3 2^
C.`C T7
FJxg9!%d
for(int i=1;;i++) [xW;5j<87
{ yh~*Kt]9Ya
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 3VNYDY`>
//Utility.log(in.readLine()); oZm)@Vv;
sHeader=httpConnection.getHeaderFieldKey(i); u*LMpTnn
if(sHeader!=null) W !TnS/O_1
{ gD`|N@W$5
if(sHeader.equals("Content-Length")) {}>s0B
{ ;pn*|Bsq
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 5Us$.p
break; _D<=Yo
} 4h% G %>j
} TKJs'%Q7F6
else IqEE.XhaK
break; zpi Q;P
} x -CTMKX
} fL-lx-~
catch(IOException e){e.printStackTrace ();} S~L;oX?(!
catch(Exception e){e.printStackTrace ();} v__n>*x
3azyqpwU$
|qe[`x; %
Utility.log(nFileLength); G':wJ7[]`
lRb|GS.h/
v0psth?qV
return nFileLength; &!Sq6<!v2
} W&MZ5t,k=
BJA&{DMHm
[{R^!Az&b<
//保存下载信息（文件指针位置） *nZe|)m
private void write_nPos() Wgp}v93
{ \piB*"ln
try{ VS.~gHx
output = new DataOutputStream(new FileOutputStream(tmpFile)); Jkf%k3H3I*
output.writeInt(nStartPos.length); LdAWCBLS
for(int i=0;i<nStartPos.length;i++) :@x_& b
{ \_GG6
// output.writeLong(nPos); Vz4/u|gt
output.writeLong(fileSplitterFetch.nStartPos); ,v^A;,q
output.writeLong(fileSplitterFetch.nEndPos); {nQ?+o3
} 5pC+*n.
output.close(); zoh%^8?o
} w~+C.4=7
catch(IOException e){e.printStackTrace ();} mV~aZM0'
catch(Exception e){e.printStackTrace ();} }J_"/bB
} R -#40
.5?e)o)
R*S9[fqC[
//读取保存的下载信息（文件指针位置） "INIP?
private void read_nPos() 5B:%##Ug5
{ *yX5g,52-|
try{ !]#@:Z
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); TPE1}8p17
int nCount = input.readInt(); ?LxBH-o(
nStartPos = new long[nCount]; %X|fp{C
nEndPos = new long[nCount]; kh7RQbNY<I
for(int i=0;i<nStartPos.length;i++) ([g[\c,H
{ kJP`C\4}f
nStartPos = input.readLong(); p"'knZG
nEndPos = input.readLong(); U!y GZEU"[
} 9-B/n0
input.close(); e^ Aw%t
} ~-J!WC==U
catch(IOException e){e.printStackTrace ();} d+m}Z>iQ1O
catch(Exception e){e.printStackTrace ();} }Mv$Up
} u)X]]6YJ
:ebu8H9f%
#aHJ|[[(n
private void processErrorCode(int nErrorCode) $V/Hr/0
{ 4`X]$.
System.err.println("Error Code : " + nErrorCode); b7uxCH]Z
} Cf~vT"
LdH23\
U))2?#
//停止文件下载 #B$r|rqamq
public void siteStop() J=l\t7w
{ :abpht
bStop = true; >Tf <8r,
for(int i=0;i<nStartPos.length;i++) Hoj'zY
fileSplitterFetch.splitterStop(); yhPO$L
xGkc_
6d;_}
} 4{v?<x8
} gl$}t H
//负责部分文件的抓取 9M]%h
**FileSplitterFetch.java Jn\@wF9xd
*/ >?L)+*^
package NetFox; D!g\-y
S\poa:D`
[Dq@(Q s'
import java.io.*; hJc^NU5
import java.net.*; (ah^</
{SRv=g
}VU7wMk
public class FileSplitterFetch extends Thread { S%6V(L|
F'^y?UP[
`Q1;Y
String sURL; //File URL Tfytc$aQ
long nStartPos; //File Snippet Start Position "KHe6otmi_
long nEndPos; //File Snippet End Position I9ZJ"29
int nThreadID; //Thread's ID s +Q'\?
boolean bDownOver = false; //Downing is over LLV1W0VO=P
boolean bStop = false; //Stop identical $/)0iL{0
FileAccessI fileAccessI = null; //File Access interface <)]j;Tl
o4qB0h
hfL8]d-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Qd"R@+i
{ ^ZD0rp(l
this.sURL = sURL; 8mnzxtk
this.nStartPos = nStart; 9O{b8=\}
this.nEndPos = nEnd; JY0}#FtgV
nThreadID = id; dfR?O#JPU
fileAccessI = new FileAccessI(sName,nStartPos);//定位 %;ZDw@_<
} gyT3[*eh
Ir?ehA
1i=p5,|
public void run() IKFNu9*"h
{ KB`">zq$u
while(nStartPos < nEndPos && !bStop) _|C T|q
{ IAFj_VWC0
"t>WM
+'`I]K>
try{ $=ua$R4Z+
URL url = new URL(sURL); jQX9KwSP
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Egm-PoPe
httpConnection.setRequestProperty("User-Agent","NetFox"); d-ML[^G
String sProperty = "bytes="+nStartPos+"-"; Fu*Qci1Z
httpConnection.setRequestProperty("RANGE",sProperty); E/Adi^
Utility.log(sProperty); /zTx+U.\I
oFDJwOJ'Bj
/8[T2Z!
InputStream input = httpConnection.getInputStream(); xN>+!&3%w
//logResponseHead(httpConnection); FNHJHuTe
_OY<Hb3%M
s g6e% 5
byte[] b = new byte[1024]; o#frNT}
int nRead; ZK?:w^Z
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ,/Yo1@U
{ )%Lgo${[;
nStartPos += fileAccessI.write(b,0,nRead); g7`uWAxZa
//if(nThreadID == 1) lfe^_`ij(+
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); e)Pm{:E
} 'l41];_
Vd+5an?
&^JYIRn1\
Utility.log("Thread " + nThreadID + " is over!"); ibxtrt=
bDownOver = true; yiAusl;
//nPos = fileAccessI.write (b,0,nRead); Zoyo:vv&
} z\6/?5D#v
catch(Exception e){e.printStackTrace ();} k}908%w
} 0$I!\y\
} 1g1gu=|Q
B[{Ie G'
^SJa/I EZ.
//打印回应的头信息 |X0Ys8f
public void logResponseHead(HttpURLConnection con) I%# e\
{ [+ N 5
for(int i=1;;i++) O#@KP"8
{ J%ue{PL7
String header=con.getHeaderFieldKey(i); F^}n7h=qk
if(header!=null) $-R9J6NN
//responseHeaders.put(header,httpConnection.getHeaderField(header)); z! DD'8r>
Utility.log(header+" : "+con.getHeaderField(header)); j.vBld
else ;h#nal>w@S
break; I.L8A|nZ
} //H3{^{
} *+>R^\uT
xOXCCf/
Fwfe5`9'
public void splitterStop() r/BiR0$E
{ >a5avSn
bStop = true; K0\Wty0
} 3I.0uLjg^
d+Bz pS@p
d$*SVd:
} }RY&f4&GV,
J6*B=PX=(
Ykt(%2L
/* <B=!ZC=n
**FileAccess.java ey3;rY1
*//文件访问(定位，写) ~zA{=|I2
package NetFox; %Q[+bN[/
import java.io.*; zFk@Y
:fE*fU@
MB]Y|Vee
public class FileAccessI implements Serializable{ {r?qI
^_^rI+cTX1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 "yV)&4)
RandomAccessFile oSavedFile; $N`uM
long nPos; ?FRQ!R
9,;+B8-A
R@H}n3,
public FileAccessI() throws IOException BlvNBB1^
{ !WReThq
this("",0); h8uDs|O9n
} u:7=Yy :
_ Oe|ZQ
gDJ@s
public FileAccessI(String sName,long nPos) throws IOException *tZ#^YG{(
{ vaEAjg*To<
oSavedFile = new RandomAccessFile(sName,"rw"); :j m|)
this.nPos = nPos; 7OOod1
oSavedFile.seek(nPos); tHo0q<.oX
} 5`3f"(ay/
.5m^)hi
^. i;,
public synchronized int write(byte[] b,int nStart,int nLen) X@7K#@5
{ 07dUBoq
int n = -1; PX1Scvi
try{ dLek4q `l
oSavedFile.write(b,nStart,nLen); 6uH1dsD
n = nLen; pY9>z;qD
} o ) FjWf;
catch(IOException e) FE/2.!]&o
{ 8Bnw//_pT
e.printStackTrace (); ^D0BGC&&
} ]Zf@NY
.W+ F<]r
WPM<Qv L
return n; XU#nqvS`.
} 9N'um%J3%s
y'k4>,`9e
C4P7,
} /fM6%V=Y
jdYv*/^
fV.43E
/* db!2nImNu\
**SiteInfoBean.java T7.u7@V2
*/ `|^<y.-6
package NetFox; E4'D4@\W
)LYj,do
^JMSe-
public class SiteInfoBean { :6z0Ep"
@zJ#16Vi
ku'%+svD
private String sSiteURL; //Site's URL XabrX|B#
private String sFilePath; //Saved File's Path 8&=+Mw
private String sFileName; //Saved File's Name 5W!E.fz*T
private int nSplitter; //Count of Splited Downloading File 6zLz<p?
CW=-@W7
EtH)E)
public SiteInfoBean() ?mt$c6-
{//nSplitter的缺省值为5 Ffm Q$>S
//default value of nSplitter is 5 | ~G;M*q
this("","","",5); LE Y Y{G?
} vAJfMUlP
z~oGd,
Ac.z6]p
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) EVj48
{ 9_ Qm_
sSiteURL= sURL; <][|,9mw
sFilePath = sPath; R^F99L
sFileName = sName; %;zWS/JhL
this.nSplitter = nSpiltter; 7q|(ZZa
DZXv3gnX
pKMf#)qm
} 7@vcQv kC
*k'9 %'<
j86s[Dty
public String getSSiteURL() m`9)DsR N
{ %'* |N[
return sSiteURL; YS{
} ,oP-:q!PC
^%d+nKx9nL
3a{QkVeV7
public void setSSiteURL(String value) hP,1;`[1
{ h3p 3~xq
sSiteURL = value; fINM$ 6
} ~9oS~fP?I
=QyO$:t
IFPywL{K
public String getSFilePath() ~ilbW|s?=k
{ (p14{
return sFilePath; N"t,6tH
} aXC`yQ?
/p>"|z
~N'KIP[W
public void setSFilePath(String value) XE$eHx3;
{ e`$v\7K
sFilePath = value; ~:)$~g7>b
} :M3l#`4Q
O:7y-r0i
6g$04C3tHi
public String getSFileName() ~*B1}#;
{ z7PPwTBa
return sFileName; lGLZIp
} RFK N,oB
\\)-[4uC
m; ABHq#
public void setSFileName(String value) S|]~,l2]}
{ Gs?W7}<$
sFileName = value; 9$DVG/
} RL&3 P@r
I;-{#OE,
?$n<vF>
public int getNSplitter() 1|gP :t}
{ KH KqE6
return nSplitter; &`TX4b^/!
} =_yOX=g|
N%B#f\N
<O>Q;}>gfc
public void setNSplitter(int nCount) Zo0&<QWj
{ ,XA;S5FE
nSplitter = nCount; Pm?6]] 7
} )%tf,3
} s*l_O*$'
|ntJ+
Pucf0 #
/* CYrL|{M]
**Utility.java _u:#2K$
*/ IWT##']G
package NetFox; ;C"J5RA
p-7dJ
v}_$9&|S
public class Utility { /BIPLDN6
If&p$pAH?
&erNVD5o
public Utility() 5;^8wh(
{ 84knoC
ev?>Nq+Z
d;;=s=j
} )nJ>kbO~8
_?r+SRFn
//线程睡眠 2d>PN^x
public static void sleep(int nSecond) ifgaBXT55
{ u\E.H5u27
try{ 16Xwtn72
Thread.sleep(nSecond); ]Pd*w`R
} .Nf*Yqs0
catch(Exception e) FFQF0.@EBi
{ 1_p'0lFe
e.printStackTrace (); [MEa@D<7N
} !c&^b@ yw
} (~OwO_|3
d)G-K+&B
//日志 qe$K6A%Yd
public static void log(String sMsg) { &qBr&kg
{ u3ZG;ykM
System.err.println(sMsg); Fu`g)#Z
} I&xRK'
Q.|2/6hD7[
>'T%=50YH
public static void log(int sMsg) ;I7Z*'5!
{ GS,pl9#V_
System.err.println(sMsg); vn_avYwiy
} @!MbPS
} foFn`?LF
aH$~':[93
:qZ^<3+:
/* drZw#b
**TestMethod.java g&bO8vR=
*/ {e@1,19
package NetFox; p&\uF#I;
@<PL
|s^ar8)=)
public class TestMethod { vLke,MKW
fU}w81oe
i!HGM=f
public TestMethod() #X8[g_d/
{ ///xx/weblogic60b2_win.exe TXaXJIp
try{ 4|e#b(!
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Ov|j{}=L=9
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Qh[t##I/
SiteFileFetch fileFetch = new SiteFileFetch(bean); w#1dO~
fileFetch.start(); t}tKm
} 4Klfnki
catch(Exception e){e.printStackTrace ();} QXz!1o+"
S&Sf}uK
zXD@M{
} g3Q #B7A
QEgv,J{
b?$09,{0
public static void main(String[] args) 8j$q%g
{ 6vA5L_
new TestMethod(); yR!>80$j
} ; M(}fV]
} [Ok8l='
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