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)); 9N%We|L,c
} D9CaFu
for(int i=0;i<nEndPos.length-1;i++) 7$vYo _
{ Pw7]r<Q
nEndPos = nStartPos[i+1]; <ro7vPKNa
} LqoB 10Kc\
nEndPos[nEndPos.length-1] = nFileLength; 6Z6'}BDP
} 6S'yZQ|b
} nJG U-Z
( iBl
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//启动子线程 +j`5F3@
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; fo*2:?K&
for(int i=0;i<nStartPos.length;i++) \Xt7`I<
{ \}u Y'F
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), (lBCO?`fx
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), LEbB(x;@
nStartPos,nEndPos,i); N ,'GN[s
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @w#-aGJO
fileSplitterFetch.start(); n/;WxnnQ
} t9kzw*U9
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $<dH?%!7
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); Z58X5"
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", {3>$[bT
nEndPos = " + nFileLength); Zw 26
// fileSplitterFetch[nPos.length-1].start(); zH?!
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~9,,~db
//等待子线程结束 ]^. _z
//int count = 0; qOIyub
//是否结束while循环 ?/wm(uL
boolean breakWhile = false; :}L[sl\R
\+oQd=K@
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while(!bStop) ="1Ind@w!
{ %B2'~|g
write_nPos(); G}9Jg
Utility.sleep(500); rKe2/4>0X
breakWhile = true; q~b&
.LPV#&
%~O,zs.2p
for(int i=0;i<nStartPos.length;i++) Maha$n*
{ tVYF{3BhA
if(!fileSplitterFetch.bDownOver) `&r+F/Ap2
{ gD-d29pQ
breakWhile = false; 4M=]wR;
break; \#2Z)Kz
} m4[;(1
} vONasD9At
if(breakWhile) /QK6Rac-
break; jnkR}wAA
I13y6= d
%^)fmu
//count++; !j8FIY'[
//if(count>4) lZd(emH@
// siteStop(); 9a[9i}_
} yJ[0WY8<kC
A]_7}<<N
a(m2n.0'>
System.err.println("文件下载结束！"); b<tNk]7
} n2"a{Ofhlf
catch(Exception e){e.printStackTrace ();} qJf?o.Pv
} ]}>2D,;
Hc;[Cs0
j"8ZM{aO
//获得文件长度 $f$SNx)),
public long getFileSize() Yj<a" Gr4[
{ lne|5{h
int nFileLength = -1; [7:,?$tC
try{ DHg:8%3x
URL url = new URL(siteInfoBean.getSSiteURL()); ^)470K`%)
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); u%GEqruo[
httpConnection.setRequestProperty("User-Agent","NetFox"); U"~>jZKk
'NbHa!
/m!BY}4W
int responseCode=httpConnection.getResponseCode(); T )&A2q
if(responseCode>=400) 9sM!`Lz{
{ }g@v`5
processErrorCode(responseCode); (fhb0i-
return -2; //-2 represent access is error DcS+_>a\{l
} j}#w)M
,=uD^n:
&.F4b~A7
String sHeader; b.OsiT;_j
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oe ~'o'
for(int i=1;;i++) Qry@ s5
{ >^O7
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Q*GN`07@?d
//Utility.log(in.readLine()); 2/U.|*mH
sHeader=httpConnection.getHeaderFieldKey(i); NYhB'C2
if(sHeader!=null) I<DL=V
{ Mg+2. 8%
if(sHeader.equals("Content-Length")) YByLoM*
{ .w:DFk^E]b
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); W PC]%:L"
break; HGl|-nW>
} {% 6}'
} ]|#+zx|/D
else 1l9G[o *
break; IM*y|UHt
} _OYasJUMG
} m1b?J3
catch(IOException e){e.printStackTrace ();} 6dHOf,zjm
catch(Exception e){e.printStackTrace ();} g%o(+d
Xa[.3=bV?
NCveSP
Utility.log(nFileLength); A]*}HZ,
/>C^WQI^
P|`8}|}a
return nFileLength; =&6eM2>P
} $+Z[K.2J
;J'LS
b\f O8{k
//保存下载信息（文件指针位置） &{5,:%PXw
private void write_nPos() 5#6|j?_a
{ t6rRU~;}
try{ 0^ _uV9r
output = new DataOutputStream(new FileOutputStream(tmpFile)); 0J*??g-n
output.writeInt(nStartPos.length); =<C:d
for(int i=0;i<nStartPos.length;i++) . P viA
{ _=r6=.
// output.writeLong(nPos); e v}S+!|U
output.writeLong(fileSplitterFetch.nStartPos); 'B$yo]
output.writeLong(fileSplitterFetch.nEndPos); kb%;=t2
} BX/8O<s0
output.close(); +:2klJ
} je\Ph5"
catch(IOException e){e.printStackTrace ();} j{ ]I]\=?
catch(Exception e){e.printStackTrace ();} e}voV0y\v:
} h#I>M`|
s3N'02G
8bGd} (
//读取保存的下载信息（文件指针位置） /A\8 mL8
private void read_nPos() Ha#=(9.
{ >fG3K`
try{ .N;=\C*
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 4(n-_BS
int nCount = input.readInt(); 3ZuZ/=
nStartPos = new long[nCount]; 5PCqYN(:B
nEndPos = new long[nCount]; e)IzQ7Zex
for(int i=0;i<nStartPos.length;i++) t|?ez4/{z
{ |T /ZL!
nStartPos = input.readLong(); HdI8f!X'TG
nEndPos = input.readLong(); ,u=`uD
} NSMyliM1Y
input.close(); YRk(u7:0
} -/B+T>[nTb
catch(IOException e){e.printStackTrace ();} f^ZRT@`O
catch(Exception e){e.printStackTrace ();} ,]C;sN%~}
} `cn#B BV
x^qVw5{n
~%F9%=
private void processErrorCode(int nErrorCode) =[ 46`-_
{ )CYGQMK
System.err.println("Error Code : " + nErrorCode); _RYxD"my
} *-WpZGh
*U-4Sy
h8j.(
//停止文件下载 3Aip}<1
public void siteStop() 0JS?;fk
{ X #dmo/L8
bStop = true; OKZV{Gja
for(int i=0;i<nStartPos.length;i++) umfD>" ^I
fileSplitterFetch.splitterStop(); N];NAMp
E =67e=h
pQ">UL*
} ]#<4vl\
} PQt")[
//负责部分文件的抓取 eIF5ZPSZi
**FileSplitterFetch.java f)rq%N &
*/ Ib!RD/
package NetFox; ;C#F>SG\S
w/<L Ag
)m+W j
import java.io.*; ssA`I<p#
import java.net.*; 9=M$AB
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2|y"!JqE1
public class FileSplitterFetch extends Thread { m 0C@G5
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,KZ~?3$yj
String sURL; //File URL \7eUw,~Q>
long nStartPos; //File Snippet Start Position "cGk)s
long nEndPos; //File Snippet End Position #zy:a%
int nThreadID; //Thread's ID ]mq|w
boolean bDownOver = false; //Downing is over 2qNt,;DQ
boolean bStop = false; //Stop identical ;d$rdFA_
FileAccessI fileAccessI = null; //File Access interface h*a(_11
C&f= ywi0
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ]cvwIc">
{ ]q[D>6_
this.sURL = sURL; aK~8B_5k8
this.nStartPos = nStart; uZYF(Yu
this.nEndPos = nEnd; 2;b\9R^>A
nThreadID = id; xa*hi87L*
fileAccessI = new FileAccessI(sName,nStartPos);//定位 I{&[[7H
} 0> E r=,e
2'Uu:Y^
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public void run() T<>,lQs(a
{ ,THw"bm
while(nStartPos < nEndPos && !bStop) nW:C/{n2tG
{ ttQGoUkj
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n&/ `
try{ ]5cT cX;Z#
URL url = new URL(sURL); UDFDJm$
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $wa{~'
httpConnection.setRequestProperty("User-Agent","NetFox"); h"W,WxL8
String sProperty = "bytes="+nStartPos+"-"; G!##X: 6'
httpConnection.setRequestProperty("RANGE",sProperty); n8[!pH~6
Utility.log(sProperty); /maJtX'
K5 z<3+
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InputStream input = httpConnection.getInputStream(); =svN#q5s
//logResponseHead(httpConnection); IPpN@
8Fh)eha9f
>y>5#[M!
byte[] b = new byte[1024]; u#~RkY7s
int nRead; :OZrH<SW
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) y^*~B(T{
{ 6@!`]tSCK
nStartPos += fileAccessI.write(b,0,nRead); ^76]0`gS
//if(nThreadID == 1) 8,%^ M9zBP
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); cjY-y-vO
} @HCVmg:
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(CL%>5V
Utility.log("Thread " + nThreadID + " is over!"); 'LC1(V!_j
bDownOver = true; !qg`/y9
//nPos = fileAccessI.write (b,0,nRead); dT8S~-d%
} Q&;9x?e
catch(Exception e){e.printStackTrace ();} _[3D
} w9imKVry
} +\A,&;!SR
mJnIwdW*
_H%c;z+
//打印回应的头信息 gf@:R'$:+
public void logResponseHead(HttpURLConnection con) `h\j99
{ ]m<$}
for(int i=1;;i++) SfyQ$$Z
{ /6*42[r
String header=con.getHeaderFieldKey(i); ,4$>,@WW~
if(header!=null) kzLsoZ!I
//responseHeaders.put(header,httpConnection.getHeaderField(header)); GxxW&y
Utility.log(header+" : "+con.getHeaderField(header)); t:Q*gWRh
else Fxz"DZY6
break; t*u:hex
} q9_OGd|P
} /3T1U
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public void splitterStop() D>q9 3;p
{ 6{b>p+U
bStop = true; yf+)6D -9n
} a=2%4Wmz
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} 6_Y,eL]"
Q2gq}c~
bG#>uE J-
/* :I#V.
**FileAccess.java :F?C)F
*//文件访问(定位，写) Lf&kv7Wj
package NetFox; 5b*C1HS@X
import java.io.*; 3w'tH4C[Y
S1_RjMbYM
sgFEK[w.y
public class FileAccessI implements Serializable{ z} #JK?u
!Vk^TFt`
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 7@Qcc t4A
RandomAccessFile oSavedFile; >[#f\bG>
long nPos; zDG b7S{
]/v[8dS(l
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public FileAccessI() throws IOException }K(TjZR
{ mfr|:i
this("",0); x%B%f`]8
} 75lA%| *X
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public FileAccessI(String sName,long nPos) throws IOException z$sT !QL~
{ \FaP|28h
oSavedFile = new RandomAccessFile(sName,"rw"); 9(Xn>G'iT
this.nPos = nPos; {JLtE{
oSavedFile.seek(nPos); :ws<-Qy
} f o3}W^0
~} ~4
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public synchronized int write(byte[] b,int nStart,int nLen) ]SEZaT
{ #'`{Qv0,
int n = -1; QT}tvm@PMq
try{ 2=}FBA,2
oSavedFile.write(b,nStart,nLen); Q>z8IlJ}
n = nLen; X?Q4}Y
} BgT*icd8d
catch(IOException e) UiNP3TJ'L
{ :`sUt1Fw.
e.printStackTrace (); DY*N|OnqJ
} ]?4hyN
|.dRily+
zH r_!~
return n; 3so%gvY.'
} zt%Mx>V@
>\8+:oS^
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} =_^X3z0
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/* !VpoZ
**SiteInfoBean.java \=o-
*/ lTsjxw o
package NetFox; %so]L+r2!
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public class SiteInfoBean { :T~[
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private String sSiteURL; //Site's URL \)e'`29;
private String sFilePath; //Saved File's Path *zLMpL_
private String sFileName; //Saved File's Name 5zJq9\)d+
private int nSplitter; //Count of Splited Downloading File Ys7]B9/1O
?7A>+EY
d(K+);!
public SiteInfoBean() tJmTBsn
{//nSplitter的缺省值为5 i30!}}N8
//default value of nSplitter is 5 x1a:u
this("","","",5); i/.6>4tE:
} ~#/
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y`Z\N
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) d zMb5puH
{ ry]l.@o;
sSiteURL= sURL; k3|Z7eW}[
sFilePath = sPath; +`15le`R
sFileName = sName; \.S/|
this.nSplitter = nSpiltter; \U0'P;em
r_d!ikOT(
SrJE_~i
} n{jGOfc
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public String getSSiteURL() Fzcwy V
{ kGJC\{N5N
return sSiteURL; 8XaQAy%d]
} u@444Vzg
$Kd>:f=A
]###w;
public void setSSiteURL(String value) HKeK<V
{ ig"L\ C"T
sSiteURL = value; ^^Vg~){4
} g{LP7D;6
R!1p^~/
z!\*Y =e
public String getSFilePath() Xc.`-J~Il
{ ABkl%m6xf
return sFilePath; sRfcF`7
} <naz+QK'
8EY:tzw
M\=2uKG#
public void setSFilePath(String value) k=^xVQuI
{ P {'b:C
sFilePath = value; D'4\*4is
} 8k79&|
<N@Gu!N8
fy$1YI>!Q
public String getSFileName() 6C)_
{ JtZ7ti
return sFileName; 6:2vP NF
} ^@]3R QB
>dT*rH3w
ce(#2o&`
public void setSFileName(String value) `X8F`5&U\f
{ w =KPT''!
sFileName = value; >d6|^h'0
} Pz^544\~ou
I:.s_8mH}
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public int getNSplitter() xC?h2hIt
{ 0IpmRH/
return nSplitter; +|rj4j)L&'
} SX*RP;vHy
~K=b\xc^
g .\[o@H
public void setNSplitter(int nCount) ~XIb\m9H
{ $8FUfJ1@
nSplitter = nCount; /O9EQPm(
} +h$ 9\
} T;#FEzBz
W8<%[-r
_G0x3
/* s@C}P
**Utility.java `{Ul!
*/ \Cj B1]I
package NetFox; o(HbGHIP
+n)9Tz5
A=4OWV?
public class Utility { ;PH~<T
n*$ g]G$
2?x4vI np;
public Utility() ME dWLFf
{ Ls%MGs9PI
[!z,lY>
+qoRP2
} 7Ix973^
)*[3Vq
//线程睡眠 D]}G.v1
public static void sleep(int nSecond) >V~E]P%@
{ [vgtc.V
try{ 36NpfTW
Thread.sleep(nSecond); yjAL\U7`T
} 5m*,8]!-
catch(Exception e) oQ#8nu{k
{ nK,w]{<wG!
e.printStackTrace (); $?Wb}DU7_L
} :r[`.`
} OCUr{Nh
'%D7C=;^
//日志 pFXEu=$3
public static void log(String sMsg) J *yg&
{ q7!{?\T%
System.err.println(sMsg); P'2Qen*
} 99S^f:t
,'+kBZOv
. ^u,.
public static void log(int sMsg) xmG<]WF>E
{ `g,..Ns-r
System.err.println(sMsg); N$DkX)Z
} R@0R`Zs
} /mMV{[
'7/)Ot(
OPi0~s
/* `gJ(0#ac
**TestMethod.java Vj-h;rB0z
*/ 7"##]m.
package NetFox; sS Mh`4'
U(Zq= M
phK/
public class TestMethod { 4JEpl'5^Q
C}X\|J
),)lzN%!
public TestMethod() ;j7#7MN2_E
{ ///xx/weblogic60b2_win.exe u y+pP!<
try{ dveiQ
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ~@!bsLSMU
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); &L:!VL{I
SiteFileFetch fileFetch = new SiteFileFetch(bean); %C0Dw\A*:
fileFetch.start(); @7u0v
} >usL*b0%
catch(Exception e){e.printStackTrace ();} @L`jk+Y0vF
,_P-$lB
5tnlrqC
} 9!GM{
G5!^*jf
UBs4K*h|
public static void main(String[] args) $:6!H:ty
{ Y@v>FlqI{
new TestMethod(); =%7-ZH9
} /xQTxh1;K
} }b}m3i1
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