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)); O=~8+sa
} ZKy)F-yX
for(int i=0;i<nEndPos.length-1;i++) s~ ||Vv!
{ cyrVz4_a
nEndPos = nStartPos[i+1]; me:~q#k
} Q&+Jeji
nEndPos[nEndPos.length-1] = nFileLength; BmR++?L
} a~q_2S]h
} fFDI qX
O'm><a>8
O<7Q>m
//启动子线程 t"x 8]Gy
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; ,I6jfXI4
for(int i=0;i<nStartPos.length;i++) M8dv y!D
{ <Hd8Jd4f
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), jr[(g:L
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), )[fjZG[
nStartPos,nEndPos,i); 'NJGez'b,
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); j5Kw0Wy7
fileSplitterFetch.start(); '!eg9}<
} !"1}zeve
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B7PkCS&X
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); KYE)#<V}@
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1 aWzd[i
nEndPos = " + nFileLength); $J6Pv
// fileSplitterFetch[nPos.length-1].start(); PD #9Z=Hj
Dl=9<:6FW
=og>& K
//等待子线程结束 8T6LD
//int count = 0; ^*sDJ #
//是否结束while循环 s%M#
boolean breakWhile = false; $HgBzZ7A2
x}\x3U
I(^pIe-
while(!bStop) {1?94rz
{ e&~vO| 3w%
write_nPos(); LGnb"ZN
Utility.sleep(500); )/HbmtXqI
breakWhile = true; n/W@H Im#
[|iWLPO1&k
0s9-`nHen|
for(int i=0;i<nStartPos.length;i++) y7CC5S?
{ g)?Ol
if(!fileSplitterFetch.bDownOver) D5Zgi!
{ yS#)F.
breakWhile = false; NOY`1i
break; k=]#)A(#C
} "PgVvm#w'
} &10l80vj
if(breakWhile) M3XG s|gw
break; ?^Gi;d5
,+w9_Gy2H
w8=&rzr8
//count++; Vn&{yCm3
//if(count>4) r]q;>\T'
// siteStop(); f^JiaU4 [
} ),{v
r ^=rs!f@
7bV(eV
System.err.println("文件下载结束！"); @jL](Mq|]
} l7h6R$7; 0
catch(Exception e){e.printStackTrace ();} B":9C'tip
} 26M:D&|ZB
sNaLz
^bM\:z"M
//获得文件长度 Borr
public long getFileSize() TWzlF>4N
{ FOPfob[
int nFileLength = -1; F u>
try{ vYFtw L`
URL url = new URL(siteInfoBean.getSSiteURL()); &}'FC7}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $>JfLSyC
httpConnection.setRequestProperty("User-Agent","NetFox"); 5)5$h]Nz>
7MWd(n-
J.EBt3
int responseCode=httpConnection.getResponseCode(); 4nsc`Hu
if(responseCode>=400) ]ilQq~X
{ 1.9bU/X
processErrorCode(responseCode); GLO%>&
return -2; //-2 represent access is error y+\kZIqX
} C/$bgK[ev
s5bqS'%
r'J="^k{
String sHeader; O]4v\~@-j
SND@#?hiO
@V?T'@W7D
for(int i=1;;i++) Vu`5/QDq
{ ?rm3Iac0S
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ,.kJF4s&
//Utility.log(in.readLine()); U[0x\~[$K
sHeader=httpConnection.getHeaderFieldKey(i); |,bP`Z
if(sHeader!=null) 4s s 4O
{ ) $`}~
if(sHeader.equals("Content-Length")) a(J@]X>'
{ @m5c<(bkfp
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); N \~}`({
break; /!#A'#Z
} <ni_78
} c;?J
else X-=4Z9
break; 3F?7oMNIh
} 0BwxPD#6bv
} |(%=zb=?X
catch(IOException e){e.printStackTrace ();} (*M*muk
catch(Exception e){e.printStackTrace ();} ~6"=d
Vp7d
MY60%
Utility.log(nFileLength); eRqPZb"6MR
pCf9"LLer
"ejsz&n
return nFileLength; kwXUjnp
} $>8O2p7W
>\!G43Q=
3PjX;U|
//保存下载信息（文件指针位置） "{S6iH)]8
private void write_nPos() BTzBT%mP
{ 1{ H=The
try{ b'ZzDYN
output = new DataOutputStream(new FileOutputStream(tmpFile)); s{Og3qUy
output.writeInt(nStartPos.length); /F$E)qN7n
for(int i=0;i<nStartPos.length;i++) P BVF'~f@j
{ vM@8&,;
// output.writeLong(nPos); vX7U|zy
output.writeLong(fileSplitterFetch.nStartPos); fN1b+d~*6
output.writeLong(fileSplitterFetch.nEndPos); Vx}e,(i
} 6HguZ_jC
output.close(); soRYM
} DfU]+;AE
catch(IOException e){e.printStackTrace ();} x5Ue"RMl+
catch(Exception e){e.printStackTrace ();} :GN++\1pw
} Z2L7US-
MQQQaD:v
v.-r %j{I
//读取保存的下载信息（文件指针位置） D^QL.Du,
private void read_nPos() hx*4xF
{ 04WxV(fo'
try{ ~ulcLvm:i
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Q:j~ kutS|
int nCount = input.readInt(); Ma'#5)D
nStartPos = new long[nCount]; Gshy$'_e
nEndPos = new long[nCount]; EJP]E)
for(int i=0;i<nStartPos.length;i++) a/v]E]=qI
{ E/hT/BOPK
nStartPos = input.readLong(); QH,Fw$1
nEndPos = input.readLong(); x=Aq5*A0
} .l hS
input.close(); ,1g_{dMx
} |ZM>UJ
catch(IOException e){e.printStackTrace ();} aX~Jk >a0
catch(Exception e){e.printStackTrace ();} V.9p4k`
} !7f,gvk
mrq,kwM
33SCHQ
private void processErrorCode(int nErrorCode) cV"Ov@_.k
{ 3GNcnb
System.err.println("Error Code : " + nErrorCode); z9:yt5ar
} jXVvVv
L|Xg4Z
M}j[{wW3
//停止文件下载 JljCI@
public void siteStop() q9H\ $
{ 8f<y~L_(`
bStop = true; t 9t '9
for(int i=0;i<nStartPos.length;i++) !MrQ-B(
fileSplitterFetch.splitterStop(); :.tL~% q
Qcks:|5
Y]_$+Si:NK
} 1{5t.
} )+"5($~
//负责部分文件的抓取 aM xd"cTzx
**FileSplitterFetch.java C(9"59>{]y
*/ Y]*&\Ex"\
package NetFox; j/_&]6!
C0K: ffv;<
Fg 8lX9L
import java.io.*; ^Vhl@
import java.net.*; CPL,QVO9
&S`g&
pGfGGY>i%
public class FileSplitterFetch extends Thread { #?k</~s6M`
|d z2Drc
>&Oql9_
String sURL; //File URL BzzZ.AH~
long nStartPos; //File Snippet Start Position `a:3S@n(}
long nEndPos; //File Snippet End Position k$ T
int nThreadID; //Thread's ID ;Xa N
boolean bDownOver = false; //Downing is over AAs&P+;
boolean bStop = false; //Stop identical zRa2iCi
FileAccessI fileAccessI = null; //File Access interface ar\K8mj
*7-rm
@e&0Wk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException }zS5o [OE
{ H] g=( %ok
this.sURL = sURL; %.D!J",\/K
this.nStartPos = nStart; /D1Lh_,2
this.nEndPos = nEnd; sa&`CEa
nThreadID = id; O_ZYm{T[7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :8j7}'
} !Vg=l[
3z, Ci$[
K,JK9)T
public void run() \EU^`o+
{ Ssuz%*
while(nStartPos < nEndPos && !bStop) /M::x+/T
{ w[\rS`J
w3"L5;oH
`Oi#`lC\
try{ AC'_#nPL#
URL url = new URL(sURL); ^a`3)WBv8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 1og+(m`BL
httpConnection.setRequestProperty("User-Agent","NetFox"); G&Dl($
String sProperty = "bytes="+nStartPos+"-"; 52 Qr
httpConnection.setRequestProperty("RANGE",sProperty); (hdu+^Qj=
Utility.log(sProperty); SASLeGaV
jI0gf&v8
'e' p`*
InputStream input = httpConnection.getInputStream(); 7i{(,:
//logResponseHead(httpConnection); 8!cHRtqK
'<YBoU{e*
Z\Ur F0
byte[] b = new byte[1024]; T&MhSJf#
int nRead; me{u~9&
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) R|'W#"{@
{ Z~QLjv&$/r
nStartPos += fileAccessI.write(b,0,nRead); xp'Q>%v
//if(nThreadID == 1) .4U*.Rf
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); n}[S
} ;1PJS_@rX
j)Ak:l%a
4bp})>}jB
Utility.log("Thread " + nThreadID + " is over!"); '2i !RT-
bDownOver = true; rm9>gKN;#
//nPos = fileAccessI.write (b,0,nRead); A7%/sMv
} 'Etq;^H
catch(Exception e){e.printStackTrace ();} (xN1?qXB.
} 2_)UHTwsK
} 9M3"'^ {$
DpvHIE:W
d"miPR
//打印回应的头信息 %7}j|eS)G
public void logResponseHead(HttpURLConnection con) 9]w?mHslE
{ NU?<bIQ
for(int i=1;;i++) p%&$%yz$
{ knYp"<qj
String header=con.getHeaderFieldKey(i); 'sH_^{V2
if(header!=null) S4 Uu/EX6S
//responseHeaders.put(header,httpConnection.getHeaderField(header)); Dol{y=(3e
Utility.log(header+" : "+con.getHeaderField(header)); DBB&6~;?
else UWqD)6
break; mICEJ\`x
} ni%)a
} d6'G 7'9
pvUV5^B(M
jq*`| m;Q
public void splitterStop() #"rK1Z
{ ;m#4Q6k)V?
bStop = true; prN+{N8YC
} Ikf[K%NKn
w-# f^#
L;$>SLl,
} isd-b]@:Lc
1w(3!Ps+
j|wN7@Zc
/* [8IO0lul+
**FileAccess.java WEe7\bWF
*//文件访问(定位，写) 4F G0'J&hw
package NetFox; o.A:29KoU
import java.io.*; SU4i'o
]#^v754X^T
@WS77d~S
public class FileAccessI implements Serializable{ CN:T$ f|)
^ex\S8j
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 -ycYQ~R
RandomAccessFile oSavedFile; mc8Q2eQat}
long nPos; e }?.3,?
QJ4$) Fr(
`3i>e<m~
public FileAccessI() throws IOException <MkvlLu((o
{ ~Ay)kv;
this("",0); HrvyI)4{
} WIf.;B)L
2{63:f1c`'
0jlM~H
public FileAccessI(String sName,long nPos) throws IOException n.2:fk
{ j\~,Gtn>Z
oSavedFile = new RandomAccessFile(sName,"rw"); =FhP$r*
this.nPos = nPos; \8QOZjy
oSavedFile.seek(nPos); ?l?l<`sTO
} =3-?$
{<gv1Yht
>x;\H(g
public synchronized int write(byte[] b,int nStart,int nLen) aF^NYe
{ 94ruQ/
int n = -1; k Alxm{
try{ }rfikm
oSavedFile.write(b,nStart,nLen); "Mj#P9
n = nLen; Ge-Bk)6
} !Z:XSF[T
catch(IOException e) ^wd@mWxx
{ v f{{z%3T
e.printStackTrace (); ?PMbbqa0
} +`k30-<P
[m0X kvd
3< ?+Yhq
return n; >bf.T7wy
} mW%8`$rVEO
F6[F~^9D
uW!XzX['
} MmjZq
lxL.ztL
^%9oeT{
/* vnvpb! @Q
**SiteInfoBean.java z eT`kZ
*/ fF0i^E<
package NetFox; T3zovnR
]5f;Kz)
{V QGfN
public class SiteInfoBean { f_S$CFa@
6Bjo9,L
}OAU5P!rp
private String sSiteURL; //Site's URL hbx4[Pf
private String sFilePath; //Saved File's Path Cj8&wz}ez
private String sFileName; //Saved File's Name `w:kY9
private int nSplitter; //Count of Splited Downloading File w!20
49QsT5b)
F*PhV|XU
public SiteInfoBean() -/JEKwc
{//nSplitter的缺省值为5 (^}t
//default value of nSplitter is 5 !\7`I}:
this("","","",5); J#Hh4Kc
} W|>jj$/o
"frZ%mv
0AQ4:KV(Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) }Kgi!$<aQx
{ _f%s]
sSiteURL= sURL; c]|vg=W
sFilePath = sPath; n;Oe-+oSC
sFileName = sName; lrv-[}}
this.nSplitter = nSpiltter; 0#J~@1Gf
1z6aMd6.
Z\IM~-
} y 9]d{:9
h(/? 81:
CXrOb+
public String getSSiteURL() eA!Z7 '
{ .A< HM}
return sSiteURL; Og7yT{h_
} AhF@
/(BS<A
]\xt[/?{
public void setSSiteURL(String value) OCx'cSs-=
{ ]XEyG7D
sSiteURL = value; ; CCg]hX
} FLMiW]?x
F6q=W#~
VxN#\Di&
public String getSFilePath() as:l1S
{ &}p\&4
return sFilePath; L}*o8l`
} 71nZi`AR
vMp=\U-~^
v8f3B<kj
public void setSFilePath(String value) #H~55))F
{ C|&tdh :g
sFilePath = value; 2X2Ax~d@
} F|F0#HC ?
yQrgOdo,w
< c^'$
public String getSFileName() 2.Vrh@FNRo
{ /+92DV
return sFileName; Cb+sE"x]
} XS&Pc
*U1*/Q.
(10t,n$
public void setSFileName(String value) QlGK+I>y;
{ ,'(|,f42
sFileName = value; X <xM '
} %0-oZL
yf:0u_&]
u<:uL
public int getNSplitter() \7LL neq
{ jv~#'=T'
return nSplitter; 0BC@wV
} oYw?kxRZ
R1LirZlzJ
y ~ K8
public void setNSplitter(int nCount) mx}5":}
{ h~#F2#.
nSplitter = nCount; \ZcI{t'a
} >k"O3Pc@
} SdlO]y9E
O<s7VHj
.\a+m
/* R9A:"sJ
**Utility.java 2@a'n@-
*/ KJT N"hF
package NetFox; DIGw4g4Kt
6Mc&=}bV
k5\V:P=#
public class Utility { t[!,puZc#
.$-;`&0cZ
9mDdX
public Utility() -I5]#%eX^
{ 9\!&c<i=
,.P]5 lE
?/&X_O
} 8 siP
[6VM4l"
//线程睡眠 )2).kL>
public static void sleep(int nSecond) <o()14
{ X{#^O/
try{ q,fp DNo
Thread.sleep(nSecond); _(f@b1O~
} c(hC'Cp
catch(Exception e) "T5jz#H#/
{ qOG@MR(5
e.printStackTrace (); bsu?Q'q
} eFs5l
} |5;,]lbt
s>G6/TTH6
//日志 65zwi-
public static void log(String sMsg) ^iEf"r
{ |h $Gs2
System.err.println(sMsg); *=@8t^fa86
} DH\Ox>b=
BMAWjEr
=Jl\^u%H(x
public static void log(int sMsg) E~q3o*
{ 9ls1y=M8J
System.err.println(sMsg); D7pQWlN\
} 1<@lM8&.kO
} 'dwsm7Xd
xqk(id\&
1N _"Mm{
/* !m\By%(
**TestMethod.java E7h@c>IK
*/ jR1^e$
package NetFox; BpA7 z/
# d"M(nt
d3EN0e+^
public class TestMethod { im<!JMI
<8%+-[(
?z)2\D
public TestMethod() q#Otp\f
{ ///xx/weblogic60b2_win.exe d.ywH;
try{ VKXi*F9
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7]u_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); 9J%O$sF
SiteFileFetch fileFetch = new SiteFileFetch(bean); J8FzQ2
fileFetch.start(); ,%m~OB#
} dT1UYG}>j
catch(Exception e){e.printStackTrace ();} \l(}8;5}
miBCq l@x
G8F;fG N
} e{2Za
0F!Uai1
fc:87ZR{K
public static void main(String[] args) ;N!n06S3
{ L9hL@
new TestMethod(); _j$V[=kdM/
} X%!?\3S
} ?>=vKU5
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