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)); >)ZX
} x_9<&Aj6
for(int i=0;i<nEndPos.length-1;i++) -r/G)Rs
{ <>aBmJs4
nEndPos = nStartPos[i+1]; 5 e:Urv77
} )6|7L)Dk
nEndPos[nEndPos.length-1] = nFileLength; `(A6uakd
} =PHl|^
} X!5N2x
b i^h&H
_`lj 3Lm0>
//启动子线程 g*b 4N_
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 9tZ)#@\
for(int i=0;i<nStartPos.length;i++) #.O,JG#H
{ :T~Aa(%(
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), l@`D;m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MWf]U
nStartPos,nEndPos,i); V~LZ%NZ8
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); YArNJ5z=
fileSplitterFetch.start(); 1|Y(XB^os(
} w+VeT@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8+vZ9!7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ?]gZg[
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @C)O[&Sk
nEndPos = " + nFileLength); lhg3 }dW
// fileSplitterFetch[nPos.length-1].start(); tB.;T0n
".L+gn}u-
j`^':!
//等待子线程结束 Wz$%o'OnC
//int count = 0; n<MMO=+bg
//是否结束while循环 A(duUl~
boolean breakWhile = false; `}o4&$
~^/zCPy[w
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while(!bStop) ja$>>5<q
{ WujIaJt-
write_nPos(); L/(e/Jalg
Utility.sleep(500); (^GVy=
breakWhile = true; Myss$gt}
<B 5^
8>x.zO_.c>
for(int i=0;i<nStartPos.length;i++) N_<sCRd]9
{ /H.QGPr
if(!fileSplitterFetch.bDownOver) \3K6NA!L
{ U`q[5U"
breakWhile = false; ^B@4 w\t
break; k*|dX.C:
} 2rHw5Wn]~
} EQPZV K/
if(breakWhile) iU^ 4a
break; -Nmf}`_
ANSvZqKh
dsDoPo0!
//count++; .;WJ(kB\U
//if(count>4) vl$! To9R"
// siteStop(); mFayU w
} Bp\io$(%
IWu^a w
vZ 4Z+;.
System.err.println("文件下载结束！"); O%9Cq}*
} )DMu`cD
catch(Exception e){e.printStackTrace ();} #%VprcEK
} <mHptgd,
X@+:O-$
&n<jpMB
//获得文件长度 |Ix6D
public long getFileSize() x$CpUy{6
{ oT 8
int nFileLength = -1; Td[w<m+p<P
try{ Ga f/0/|
URL url = new URL(siteInfoBean.getSSiteURL()); 0w\X
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); DjOFfD\MF
httpConnection.setRequestProperty("User-Agent","NetFox"); B0=:A
mDE{s",q/
9BI5qHEp
int responseCode=httpConnection.getResponseCode(); 4 E3@O
if(responseCode>=400) ,- ]2s_
{ {+c/$4<
processErrorCode(responseCode); )$q<"t\#P#
return -2; //-2 represent access is error 1E$Z]5C9
} xy mK|
2`5(XpYe
f<SSg*A;
String sHeader; jbIWdHZ/US
NOyLZa'
oE#HI2X
for(int i=1;;i++) %fP^Fh
{ UQ|0Aqwq
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 6AUzS4O
//Utility.log(in.readLine()); U]vNcQj
sHeader=httpConnection.getHeaderFieldKey(i); (m;P,*
if(sHeader!=null) lk.Q6saI1
{ 3JW9G04.
if(sHeader.equals("Content-Length")) t{~"vD9Am
{ #a#~YSnG
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); n_Um)GI>
break; x(}tr27o
} 0IDHoNaT<
} ^e@c Ozt
else 1bzPBi
break; CyG@
} bG^eP:r
} `m2F.^qrr
catch(IOException e){e.printStackTrace ();} 6/4OFvL1
catch(Exception e){e.printStackTrace ();} tB(Q-c
uzp!Y&C
W[^XG\
Utility.log(nFileLength); u"T5m
d,<ctd
4] ?
return nFileLength; \!cqeg*53
} hNx`=D9[7
1MB
u x:,io
//保存下载信息（文件指针位置） )>\Ne~%
private void write_nPos() Q]6nW[@j'
{ ?'T>/<(
try{ $Fr2oSTT)
output = new DataOutputStream(new FileOutputStream(tmpFile)); NmB0CbB
output.writeInt(nStartPos.length); !Z=`Wk5
for(int i=0;i<nStartPos.length;i++) g<,v2A
{ Eq.c;3
// output.writeLong(nPos); Tr@`ozp8
output.writeLong(fileSplitterFetch.nStartPos); ?5B}ZMW
output.writeLong(fileSplitterFetch.nEndPos); AO']Kmm
} a*SJHBB
output.close(); qsJA|z&6x
} QJ"Bd`wc
catch(IOException e){e.printStackTrace ();} vpXS!o>/Sn
catch(Exception e){e.printStackTrace ();} 2YwV}
} 5j]}/Aq
dDpe$N
N#,4BU
//读取保存的下载信息（文件指针位置） ORtl~V'
private void read_nPos() |qI_9#M\(
{ m7M*)N8
try{ =,T~F3pK
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #v&&GuF
int nCount = input.readInt(); ;U20g:K
nStartPos = new long[nCount]; W{-N,?z
nEndPos = new long[nCount]; f2{4Y)
for(int i=0;i<nStartPos.length;i++) :nwcO3~`
{ GuDus2#+
nStartPos = input.readLong(); }1_gemlf
nEndPos = input.readLong(); Wb4sfP_
} c&0IJ7fZG
input.close(); l>=c]
} 9l,Gd
catch(IOException e){e.printStackTrace ();} *\joaw
catch(Exception e){e.printStackTrace ();} vxqMo9T
} Szg<;._J
#Jm_~k
'|]zBpz
private void processErrorCode(int nErrorCode) 8tdUnh%/
{ sWX
System.err.println("Error Code : " + nErrorCode); P%/+?(?
} "V9!srIC
RisrU
*K+*0_
//停止文件下载 G %#us3x
public void siteStop() F5MWxAS,>
{ s#d# *pgzh
bStop = true; ZnJnjW PQ
for(int i=0;i<nStartPos.length;i++) x(t}H8q
fileSplitterFetch.splitterStop(); '6xn!dK
VS}Vl
gH_r'j
} +-.BF"}
} 1%-?e``.
//负责部分文件的抓取 MiSFT5$v6
**FileSplitterFetch.java Ab(bvS8r$
*/ mR0@R;,p
package NetFox; (+^1'?C8
+m+HC(Z
W:) M}}&H
import java.io.*; [{zekF~)@
import java.net.*; +6;OB@
#); 6+v
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public class FileSplitterFetch extends Thread { |RjjP 7
BryMq !
{K|{a
String sURL; //File URL }F3Z~
long nStartPos; //File Snippet Start Position lhjPS!A~
long nEndPos; //File Snippet End Position ]3I_H+hU
int nThreadID; //Thread's ID tjTF?>^6|
boolean bDownOver = false; //Downing is over ';lO[B
boolean bStop = false; //Stop identical u#P7~9ZG-
FileAccessI fileAccessI = null; //File Access interface sV*Q8b*
A{c6XQR~z
,%jJ ,G,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException -#i%4[v
{ nut7b
this.sURL = sURL; K3Xy%pqR#
this.nStartPos = nStart; S\X_!|
this.nEndPos = nEnd; un/eS-IIh
nThreadID = id; N&ddO-r[s
fileAccessI = new FileAccessI(sName,nStartPos);//定位 0SDCo\
} au7BqV!uL
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public void run() )l"0:1Ig
{ },"g*
while(nStartPos < nEndPos && !bStop) '*-SvA\Cx
{ +amvQ];?Q8
%EpK=;51U
K:Ap|F
try{ vd;wQ
URL url = new URL(sURL); Wu}Co
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ._R82gy
httpConnection.setRequestProperty("User-Agent","NetFox"); "d#s|_n,d)
String sProperty = "bytes="+nStartPos+"-"; #zQkQvAT9
httpConnection.setRequestProperty("RANGE",sProperty); rvG qUmSUs
Utility.log(sProperty); cK258mY
NMDNls&)k
t #AQD]h
InputStream input = httpConnection.getInputStream(); Iq5F^rH`[
//logResponseHead(httpConnection); U-k;kmaj
|'J3"am'
i3GvTg-X
byte[] b = new byte[1024]; ;'Y?wH[
int nRead; -@73"w/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) cn#a/Hx
{ yO($KL+
nStartPos += fileAccessI.write(b,0,nRead); 54OYAkPCk
//if(nThreadID == 1) V|D;7
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nJ?C4\#3
} 4a 5n*6G!
y, Z#?O
=#u2Rx%V
Utility.log("Thread " + nThreadID + " is over!"); h1Lp:@:|
bDownOver = true; \uYUX~}i"
//nPos = fileAccessI.write (b,0,nRead); $-y+97
} 646yeQ1
catch(Exception e){e.printStackTrace ();} M&K@><6k,k
} ufJFS+?
} nqH^%/7)A@
Q?>#sN,
pqs)ueu
//打印回应的头信息 5[3hw4
public void logResponseHead(HttpURLConnection con) ,'9tR&S$_
{ Cam}:'a/`
for(int i=1;;i++) V":BAn
{ dbLX}>
String header=con.getHeaderFieldKey(i); GBQb({
if(header!=null) kgIWgk%
//responseHeaders.put(header,httpConnection.getHeaderField(header)); b'OO~>86
Utility.log(header+" : "+con.getHeaderField(header)); ELPJ}moWZ
else wx!*fy4hL
break; 9t[278B6
} fH.W kAE1
} R*y[/Aw
/;0>*ft4
d3$<|mG$
public void splitterStop() )k1,oUx
{ <d^7B9O?&w
bStop = true; Mz^s^aJEE
} mx[^LaR>v
iF0a
~Qsj)9
} $O>@(K
Jv<)/Km`
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/* g#:XN
**FileAccess.java GW#kaqC1
*//文件访问(定位，写) :2My|3H\
package NetFox; z]YhQIU4n8
import java.io.*; ob7_dWAG
'k67$H
^;3rdBprm
public class FileAccessI implements Serializable{ rrWk&;?
L8zqLDi&
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 a7|&Tbv
RandomAccessFile oSavedFile; ;40m goN
long nPos; <f6PULm
J){\h-4
ZX;k*OrW
public FileAccessI() throws IOException }^<zVdwp
{ O}-7 V5
this("",0); {|h"/
} Qzhnob#C9
-X[[ OR9+
\?^wu
public FileAccessI(String sName,long nPos) throws IOException PQ]9xzOg[
{ G7;}309s
oSavedFile = new RandomAccessFile(sName,"rw"); EM*OrUe
this.nPos = nPos; LPn}QzH
oSavedFile.seek(nPos); #<PdZl R
} 5Nb_K`Vp*
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5)7mjyo%
public synchronized int write(byte[] b,int nStart,int nLen) /vDF<HVzm
{ 2S6EDXc
int n = -1; Q/n.T0Z^
try{ ;QQ7vo
oSavedFile.write(b,nStart,nLen); .^S78hr]n
n = nLen; BznA)EK?@
} kV3j}C"
catch(IOException e) b6Hk20+B;
{ vx@p;1RU`
e.printStackTrace (); k#5e:VOb
} }.cmiC
cu^*x/0,
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return n; +i#sS19h
} TQd FC\@f"
u2BW]T]
].P(/~FS9
} QeJ.o.m{
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25c!-.5D
/* (+8xUc(w
**SiteInfoBean.java ;T{/;
*/ OG+r|.N;
package NetFox; 0o$HC86w
>X,Ag
KbdfSF$
public class SiteInfoBean { Z)i1?#
([CnYv
x<j"DS}S)D
private String sSiteURL; //Site's URL ?U/Wio$@
private String sFilePath; //Saved File's Path UX'NJ1f
private String sFileName; //Saved File's Name -0o6*?[Z
private int nSplitter; //Count of Splited Downloading File 0 ;_wAk
JX/4=..
_#D\*0J
public SiteInfoBean() d<Q+D1
{//nSplitter的缺省值为5 +%qSB9_>N{
//default value of nSplitter is 5 QiE<[QP{g
this("","","",5); o+_/)c
} V"by9p|V`
TflS@Z7C
9g &Ch9-/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) BZ;}ROmqk
{ Ym.l@(
sSiteURL= sURL; Rs F3#H
sFilePath = sPath; G(OT"+O,
sFileName = sName; nN`Z0?
this.nSplitter = nSpiltter; '<&EPUO
X'#$e{
}\939Y
} ]]=-AuV.
U 'CfP9=
myWmU0z/
public String getSSiteURL() TG63
{ !jnqA Z
return sSiteURL; [Ql?Y$QB`4
} b4)*<Zp`
h lkvk]v
(}FW])y
public void setSSiteURL(String value) %g0z)J
{ s"=F^#
sSiteURL = value; l!;_lH8W$
} CaYos;Pl
` -[Bo
H6ky)kF&
public String getSFilePath() HZDaV&)@
{ YQ@dl
return sFilePath; \)otu\3/
} uRm_
prlyaq;4
G/fP(o-Wd
public void setSFilePath(String value) c+8>EU AW
{ Oj"pj:fB
sFilePath = value; UbY~xs7_
} Q"_T2fl]vP
$m:2&lU3
8|5Gv
public String getSFileName() UH 47e
{ X;OsH
return sFileName; @.Z[M
} >[|GC/C
< QDr,Hj
i'W_;Y}
public void setSFileName(String value) Y]~ HAv '
{ mq J0z4I}
sFileName = value; R=vbUA
} 8h&oSOkQk,
I|g@W_
NK7H,V}T
public int getNSplitter() }uF[Ra
{ 1V|< A
return nSplitter; V3>f*Z)xn
} JrCf,?L^
tt6. jo
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public void setNSplitter(int nCount) $ \Q<K@{
{ g08*}0-k
nSplitter = nCount; k4qLB1&,
} ;cv.f>Cm
} bz,Da
(KT38RhA
MU_!&(X_
/* J)9 AnGWe
**Utility.java VHXI@UT*
*/ $}qDV> qo
package NetFox; 0+T*$=?
ZYE' C
H$z>OS_6U
public class Utility { BFBR/d[&
m b%C}8D
W(;x\Nc7
public Utility() zKIGWH=qqm
{ ;_mgiKHg
]3n, AHA
R%>jJ[4\[
} b8rp8'M)
W|)GV0YM
//线程睡眠 99<4t$KH
public static void sleep(int nSecond) E%<w5d.lq
{ vuYO\u+ud
try{ }1QI"M*
Thread.sleep(nSecond); fNmE,~
} <RhOjZgyZ
catch(Exception e) 2dHM
{ WMW1B}Z3
e.printStackTrace (); an3~'g?
} ;tJWOm
} %lN2n,AK
!\QeBd+
//日志 wk" l[cH>
public static void log(String sMsg) 3(1]FKZtt
{ b6 $,Xh
System.err.println(sMsg); TqIAWbb&
} "gFxfWIA
s(Z(e %
YTQ5sFuGM
public static void log(int sMsg) j]rXoV>
{ /+>)"D6'
System.err.println(sMsg); ZTN(irK
} &|)hCJu
} $j57LY|r
js~tKUvg
F"!agc2!
/* "[k1D_PZ
**TestMethod.java {S G*
*/ 2;8Xz6T
package NetFox; $30oc Tt{
J0=7'@(p
UcgG
public class TestMethod { rVY?6OMkd
t{!/#eQC
)IQ*
public TestMethod() X:>$8^gS
{ ///xx/weblogic60b2_win.exe `)T&~2n
try{ >QXzMN}o
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); n|WfaJQZ
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); m+?N7
SiteFileFetch fileFetch = new SiteFileFetch(bean); |pJC:woq
fileFetch.start(); t#Th9G]1
} qP7G[%=v
catch(Exception e){e.printStackTrace ();} %;7.9%
q(78fZ *X
cph~4wCS[U
} t-WjL@$F/
_pW_G1U
%,/lqcFo
public static void main(String[] args) Jy]Id*u9
{ n@hl2M6.x9
new TestMethod(); qe?Qeh(!X
} )>\4ULR83
} zN%97q_
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