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)); p!5JO4F$
} D +%k1
for(int i=0;i<nEndPos.length-1;i++) /o3FK
{ Hw-oh?=
nEndPos = nStartPos[i+1]; < $/Yw
} sA7K ;J})
nEndPos[nEndPos.length-1] = nFileLength; tfU3 6PR
} /3HWP`<x
} _1bd)L&dF
m##z
HK4`@jYQ
//启动子线程 XhkL))FcG
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; NNrZb?
for(int i=0;i<nStartPos.length;i++) x@(f^P
{ WYd,tGz
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), W}i$f -K
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), MrjB[3Td
nStartPos,nEndPos,i); %^BOYvPx
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); WX$^[^=HC
fileSplitterFetch.start(); 544I#!
} (N>ew)Ke
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), CX2q7azG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :JG}%
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", uS10P7N}
nEndPos = " + nFileLength); 9>Z#o<*_/
// fileSplitterFetch[nPos.length-1].start(); iPL'JVPZ
K%#C+`Ij
&wC.?w$
//等待子线程结束 %LaC$w_X
//int count = 0; N=q29JU
//是否结束while循环 a5+v)F/=
boolean breakWhile = false; [t\Mu}b
3cQmxp2*
,#FH8%Yf
while(!bStop) tQ<2K*3]
{ NjMLq|X
write_nPos(); H[yLlv
Utility.sleep(500); #6Ph"\G/
breakWhile = true; 2PW3S{Dt
.aRxqFi_
xqZ%c/I3q
for(int i=0;i<nStartPos.length;i++) G+yz8@
{ ~_\2\6%1^n
if(!fileSplitterFetch.bDownOver) @Bwl)G!|
{ !a&F:Fbm
breakWhile = false; <%5uzlp
break; 545xs`Q_
} #SUq.A
} `I:,[3_/
if(breakWhile) +0042Yi
break; n8ya$bc
Q&\ksM
/JYi^rZ
//count++; I>zn$d*0
//if(count>4) h^X.e[
// siteStop(); l3$?eGGM
} U?C{.@#w
O/"&?)[v
7im;b15j`'
System.err.println("文件下载结束！"); FAGVpO[
} U9OF0=g
catch(Exception e){e.printStackTrace ();} (G;*B<|A
} R-|]GqS}L
d$ 7b
)y Y;%
//获得文件长度 bhT]zsBK
public long getFileSize() 2UJ0%k
{ : \`MrI^
int nFileLength = -1; =l_"M
try{ ~1!kU4
URL url = new URL(siteInfoBean.getSSiteURL()); 'hWRwP|
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); =ZL20<TeH
httpConnection.setRequestProperty("User-Agent","NetFox"); XV!EjD~q
j<5R$^?U
$dUN+9
int responseCode=httpConnection.getResponseCode(); 8=Ht+Br
if(responseCode>=400) \OB3gnR
{ 6g&nnA
processErrorCode(responseCode); \Ki#"%S
return -2; //-2 represent access is error 5jk4k c
} .U {JI\
S-dV
rrq-so1u}
String sHeader; )Jn80~U|1
Q)8t;Kx
7 4UE-H)
for(int i=1;;i++) XcneH jpR
{ $*ZHk0 7x
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); PUArKBYM-
//Utility.log(in.readLine()); 1(a\$Di
sHeader=httpConnection.getHeaderFieldKey(i); u'][3
if(sHeader!=null) .;s4T?j@w
{ >iV(8EgBS
if(sHeader.equals("Content-Length")) ;c}];ZU3G
{ +r"$?bw'
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W5{e.eI}|
break; n&JP/P3Y
} Ss}0.5Bq
} b@Cvs4
else ^5F/=TtE G
break; aT[7L9Cw
} Z2 4 m
} ay.IKBXc
catch(IOException e){e.printStackTrace ();} 4[wP$
catch(Exception e){e.printStackTrace ();} :r=_\?
Pl>t\`1:|A
BO|Jrr>
Utility.log(nFileLength); -OxHQ
a#=-Aj-
r8$TT\?~
return nFileLength; QJ?!_2Ax
} 5#PhaVc
m+ YgfR
]y e&#
//保存下载信息（文件指针位置） v8[1E>&vx
private void write_nPos() $%'z/'o!
{ ~E~J*R Ze
try{ ^DOcw@Z6HC
output = new DataOutputStream(new FileOutputStream(tmpFile)); fZC,%p
output.writeInt(nStartPos.length); Y#,MFEd
for(int i=0;i<nStartPos.length;i++) l|{<!7a
{ v2Y=vr
// output.writeLong(nPos); ){~.jP=-#
output.writeLong(fileSplitterFetch.nStartPos); hd' n"
output.writeLong(fileSplitterFetch.nEndPos); N0f}q1S<-A
} Y'9deX+
output.close(); \8ZNXCP
} g(^l>niF:
catch(IOException e){e.printStackTrace ();} :z7!X.*
catch(Exception e){e.printStackTrace ();} V"XN(Fd^
} ,8seoX^
ai RNd~\
cCIEG e6
//读取保存的下载信息（文件指针位置） mLO6`]p{H
private void read_nPos() )ej8vm
{ `1gsrHi4N
try{ 4j5 "{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); WP9=@X Z
int nCount = input.readInt(); :C5N(x
nStartPos = new long[nCount]; 7_,X9^z
nEndPos = new long[nCount]; crQuoOl7
for(int i=0;i<nStartPos.length;i++) dmne+ufB
{ 2NM}u\%c/
nStartPos = input.readLong(); ;a"Ukh
nEndPos = input.readLong(); YQOGxSi
} T7`Jtqf
input.close(); v.MWO]L
} 4m:E:zVn
catch(IOException e){e.printStackTrace ();} vbp)/I-h
catch(Exception e){e.printStackTrace ();} $6N.ykJ
} +]X^bB[
yI)2:Ca*
v*pVcBY>
private void processErrorCode(int nErrorCode) RD^o&VXO
{ 2#!D"F
System.err.println("Error Code : " + nErrorCode); 3h&s=e!
} Z)<>d.
<_~`)t
42M3c&@P
//停止文件下载 (iFhn*/ E
public void siteStop() qM)^]2_-
{ -c tZ9+LL
bStop = true; })Jp5vv
for(int i=0;i<nStartPos.length;i++) _]g6 3q
fileSplitterFetch.splitterStop(); s$;v )w$
UZ$p wjC
;%}
} J{Jxb1:c
} 4{TUoI6ii
//负责部分文件的抓取 rlq8J/0/+
**FileSplitterFetch.java j,Y=GjfGM
*/ W$W7U|Z9y+
package NetFox; tF4"28"h
z|Xl%8
LS`Gg7]S
import java.io.*; oKUJB.PF
import java.net.*; P7n~Ui~U
;rX4${h
X!m/I i$q
public class FileSplitterFetch extends Thread { ty ~U~
^t"\PpmK<d
ji "*=i
String sURL; //File URL OP@PB|
long nStartPos; //File Snippet Start Position _<8n]0lX3
long nEndPos; //File Snippet End Position \*7Tj-#
int nThreadID; //Thread's ID `k+k&t
boolean bDownOver = false; //Downing is over y(HR1vQ;Z
boolean bStop = false; //Stop identical e>[QF+e)y
FileAccessI fileAccessI = null; //File Access interface %}@^[E)
&\A$Rj)
F[lHG,g-
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x|Dj
{ |cH\w"DcXw
this.sURL = sURL; TSOt$7-
this.nStartPos = nStart; p8Pvctc
this.nEndPos = nEnd; ?@ O[$9y
nThreadID = id; wXP1tM8T
fileAccessI = new FileAccessI(sName,nStartPos);//定位 {x+jFj.
} W!{uEH{%l
qhogcAvE
9T\:ID=h
public void run() SpkD
{ 9%x[z%06
while(nStartPos < nEndPos && !bStop) \ZA%"F){
{ pJqayzV
)|:|.`H
1\1o65en
try{ (+_Amw!W
URL url = new URL(sURL); 2a{eJ89f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); >q`G?9d2
httpConnection.setRequestProperty("User-Agent","NetFox"); %P?W^mI
String sProperty = "bytes="+nStartPos+"-"; `H\^#Zu
httpConnection.setRequestProperty("RANGE",sProperty); rHMsA|xz6
Utility.log(sProperty); t{$t3>p-t
hHdC/mR
TOQvZ?_
InputStream input = httpConnection.getInputStream(); | #,b1|af
//logResponseHead(httpConnection); +!X^E9ra
sGV%O=9?2
wJ{M&n1H
byte[] b = new byte[1024]; >4;A(s`
int nRead; ydpsPU?wj5
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) SgJQH7N
{ VBOq~>V6(v
nStartPos += fileAccessI.write(b,0,nRead); )UWE.oBI
//if(nThreadID == 1) vJYy`k^Y
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jvW/M.q4
} Od!j+.OY<
;yH/GN#O
?R";EnD
Utility.log("Thread " + nThreadID + " is over!"); vsc&$r3!5{
bDownOver = true; rXA7<_Vg
//nPos = fileAccessI.write (b,0,nRead); wsM5TB
} Fd2zvi
catch(Exception e){e.printStackTrace ();} *'Ch(c:rtH
} 7-)Y\D
} )=~1m85+5B
!x>P]j7A}Y
+&|WC2#
//打印回应的头信息 zF{5!b
public void logResponseHead(HttpURLConnection con) srUpG&Bcx
{ K{N#^L!
for(int i=1;;i++) *NDzU%X8
{ ^58'*13ZL
String header=con.getHeaderFieldKey(i); ) ><{A
if(header!=null) .t\5H<z
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 4%B${zP(.}
Utility.log(header+" : "+con.getHeaderField(header)); #[IQmU23
else ?!Y2fK=h0
break; "xw2@jGpG
} Z[|(}9v?~
} N1_nBQF )
^/c&Ud
=8[HC}s|$
public void splitterStop() aVd{XVE
{ ~W!sxM5(*
bStop = true; LTrn$k3}
} 1'M<{h<sP
--y.q~d
I(pU_7mw
} P*G&pitT
kpEES{f
$BCqz! 4K
/* Si!W@Jm
**FileAccess.java w+ bMDp
*//文件访问(定位，写) RoPz?,u
package NetFox; BH\qm (X
import java.io.*; aiea&aJ
zf#V89!]C"
wOINcEdx
public class FileAccessI implements Serializable{ EY':m_7W
6MF%$K3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 tFXG4+$D
RandomAccessFile oSavedFile; Ot5 $~o
long nPos; W&)OiZN
t[%9z6t
DqbN=[!X~n
public FileAccessI() throws IOException [K,&s8N5
{ 6dV92:
this("",0); ACc.&,!IZ
} >AV?g8B;
-49OE*uF
_<&IpT{w+
public FileAccessI(String sName,long nPos) throws IOException KD=T04v
{ J %URg=r
oSavedFile = new RandomAccessFile(sName,"rw"); u JGYXlLE
this.nPos = nPos; }Z"<KF
oSavedFile.seek(nPos); F(:+[$)
} ` Y"Rh[C
27}k63\
pJ1GB
public synchronized int write(byte[] b,int nStart,int nLen) uG~%/7Qt{
{ D:M0_4S
int n = -1; >i-cR4=LL{
try{ 0~Z2$`(
oSavedFile.write(b,nStart,nLen); =#SKN\4
n = nLen; YB.r-c"Y
} UPA))Iv>
catch(IOException e) E:L =>}
{ ^7V9\Q9
e.printStackTrace (); VWaI!bK
} UIIR$,XB
3L/>=I{5
JmtU>2z\
return n; w*OZ1|
} D\bW' k]!
.^fq$7Y}7
esWgYAc3{
} ySL 31%
7{2knm^
+3!um
/* `dx+Qp
**SiteInfoBean.java JO1KkIV
*/ :TxfkicN\
package NetFox; M8Q-x-7
dt<PZ.
[wi "
public class SiteInfoBean { v_En9~e^n
P] ouLjyq
zsc8Lw
private String sSiteURL; //Site's URL \|L@
private String sFilePath; //Saved File's Path \2*<Pq
private String sFileName; //Saved File's Name VrrCW/o
private int nSplitter; //Count of Splited Downloading File !i2=zlpb[
?yU|;my
&Dgho
public SiteInfoBean() pg;agtI
{//nSplitter的缺省值为5 S2@[F\|r
//default value of nSplitter is 5 120<(#
this("","","",5); D9 OS,U/l
} ebcGdC/%>
,g;~:
,yNPD}@v>
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) .yd{7Te
{ 80x %wCY`
sSiteURL= sURL; 3 8m5&5)1F
sFilePath = sPath; Y, )'0O
sFileName = sName; }[SWt3qV1
this.nSplitter = nSpiltter; %F` cNw]
k^:$ETW2 D
j]6Z*AxQ
} &Ru|L.G`
g~S>_~WL
eo24I0`N
public String getSSiteURL() k*\WzBTd
{ !=_:*U)-'
return sSiteURL; x}?y@.sn8
} cO.U*UTmX
~ b!mKyrZ
:MV]OLRM
public void setSSiteURL(String value) W7c(] tg.
{ J$%mG*Y(
sSiteURL = value; yNoJrA
} +^iUY%pm
By]XD~gcP
kOmTji7
public String getSFilePath() U@@#f;&
{ Nq/,41
return sFilePath; FVPhk2
} H 0aDWFWS
~*GJO74
h \hQ
public void setSFilePath(String value) 5?&k? v@
{ rbHrG<+7zO
sFilePath = value; :Ag]^ot
} u-=S_e
>k,bHGj?
#I'W[\l~+
public String getSFileName() `(vgBz`e[
{ x}[/A;N
return sFileName; <UQaRI[55
} /V+&#N
Jx9S@L`
I,(m\NalK
public void setSFileName(String value) 5?r#6:(yI
{ @Kd1|K
sFileName = value; )l[<3<@s
} e#(0af8A
bIu'^
>Vy=5)/i
public int getNSplitter() o3P`y:&
{ QrDzfe[
return nSplitter; +AhR7R!
} O8(;=exA
I\&..e0l
\bw71( Q
public void setNSplitter(int nCount) PspH[db
{ qAUqlSP5
nSplitter = nCount; \K.i8f,
} 2f9~:.NgF
} p+SFeUp
}{[H@uhjH
FbO-K-
/* (cAv :EKpo
**Utility.java +Pd&YfU9
*/ _A|1_^[G(
package NetFox; ,UopGlA ,
4(o: #9I
z9}rT<hy
public class Utility { Q6@}t&k4C
=G]} L<
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public Utility() $~`a,[e<
{ =24)`Lyb
D|/Azy.[
A)Wp W M
} "#z4
ck>|p09q'9
//线程睡眠 5V!L~#
public static void sleep(int nSecond) C18pK8-
{ y:WRpCZoa
try{ 7}(wEC
Thread.sleep(nSecond); lEIX,amwa
} ](a*R
catch(Exception e) #Z;ziM:
{ A8&yB;T$y
e.printStackTrace (); -sm{Hpf_b
} 4Z)`kS}=]
} {:xINQ=}D
*M\Qt_[
//日志 U>7"BpC
public static void log(String sMsg) hSSF]
{ 0kS[`a(}J
System.err.println(sMsg); ]|18tVXc
} zDeh#
x tg3~/H
;29q
public static void log(int sMsg) !SEHDRp
{ $'btfo4H
System.err.println(sMsg); LbOjKM^-
} &>\E >mJ
} x^^;/%p
O9wZx%<
-U)6o"O_CV
/* aF2eGh
**TestMethod.java #~*fZ|sq+3
*/ +6@".<
package NetFox; I~y[8
3C 84b/A
${0+LhST
public class TestMethod { k<wX??'
vNlYk
gm~Ka%O|F
public TestMethod() NX&mEz
{ ///xx/weblogic60b2_win.exe 8.HqQ:?&2t
try{ L3lf28W
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); G 5w:
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _;3xG0+
SiteFileFetch fileFetch = new SiteFileFetch(bean); "]>JtK
fileFetch.start(); 9Xo'U;J
} g#ubxC7t<
catch(Exception e){e.printStackTrace ();} ^eQK.B(
o7S,W?;=5
<^6|ZgR
} %>`0hk88
Os' 7h
P9; =O$s
public static void main(String[] args) Lo _5r T"
{ KArt4+31
new TestMethod(); D@*<p h=
} W4Rs9NA}
} ; S7 %
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