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)); hm! J@
} <1l%|
for(int i=0;i<nEndPos.length-1;i++) jts0ZFHc-
{ iX]OF.:
nEndPos = nStartPos[i+1]; )>:~XA|?
} A}(]J!rc
nEndPos[nEndPos.length-1] = nFileLength; A-T-4I
} _&hM6N
} W~;Jsd=f
u9OY Jo
LSou]{R
//启动子线程 RI&O@?+U
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; P'lnS&yA
for(int i=0;i<nStartPos.length;i++) FL^ _)`
{ -&>V.hi7
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9 A ?{}c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), =wdh#{
nStartPos,nEndPos,i); R+Hu?Dv&F
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U 5J _Y
fileSplitterFetch.start(); LJ/He[r|[
} gHBvQ1g
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 1fS&KO{a
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); KD &nLm!
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 1"ZtE\{ "
nEndPos = " + nFileLength); +9b{Y^^~T
// fileSplitterFetch[nPos.length-1].start(); KHML!f=mu
>nghFm
DJ,LQj
//等待子线程结束 w~b:9_reY
//int count = 0; ]u|v7}I4
//是否结束while循环 n9+33^ PT
boolean breakWhile = false; FtIcA"^N
LUMbRrD-
iAu/t
while(!bStop) [! $NTt_
{ Y7}Tuy dC
write_nPos(); pY"WW0p"C
Utility.sleep(500); &L+uu',M0c
breakWhile = true; \Mg_Q$
1n8[fgz
e.n(NW
for(int i=0;i<nStartPos.length;i++) z!"vez
{ 3Tl<ST\
if(!fileSplitterFetch.bDownOver) \9VF)Y.ke
{ Q6qW?*Y
breakWhile = false; (4+P7Z,Nc
break; wsWFD xR
} {=ox1+d
} SV>tw`2
if(breakWhile) =9jK\ T^
break; A9MM^jV8
<giBL L!
10FiA;
//count++; ^9[Q;=R
//if(count>4) 13X}pnW
// siteStop(); Food<(!.>
} Y~I<Locv
b"h'7C/
Jbu2y'zE
System.err.println("文件下载结束！"); $y8-JR~
} 1D*=ZkA)
catch(Exception e){e.printStackTrace ();} 1|MRXK
} B}iEhWO6
h3CA,$HJ
1hG#
//获得文件长度 +-!E%$
public long getFileSize() H$h#n~W~
{ j<p.#jkT
int nFileLength = -1; I%3[aBz4
try{ U N9hZ>9
URL url = new URL(siteInfoBean.getSSiteURL()); XIdh9)]^}
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 32YbBGDN!f
httpConnection.setRequestProperty("User-Agent","NetFox"); ;o9h|LRs
dht0PZdx?
=u<:'\_
int responseCode=httpConnection.getResponseCode(); 8<6H2~5<
if(responseCode>=400) [SPx
{ MVYd\)\o
processErrorCode(responseCode); DzAZv/h76
return -2; //-2 represent access is error ;V}:0{p
} {~U3|_"[pX
yH/A9L,Z
.e~"+Pe6b
String sHeader; UT<e/
5RP kAC
.{V"Gn9!
for(int i=1;;i++) $'J3 /C7
{ 6zi>Q?] 1
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); <CyU9`ye
//Utility.log(in.readLine()); ]q]xU,
sHeader=httpConnection.getHeaderFieldKey(i); hYW9a`Ht/
if(sHeader!=null) }|DspO
{ Oidf\%!mvR
if(sHeader.equals("Content-Length")) Qm%PpQ^Lz3
{ |bY@HpMp
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JusU5 e|
break; EwP2,$;
} Y sM*d
} |b
else ORExI.<`W
break; }t H$:Z
} r]3-}:vU
} VXeO}>2S
catch(IOException e){e.printStackTrace ();} EgjJywNhd2
catch(Exception e){e.printStackTrace ();} F$7!j$ Z
n>Ff tVZNJ
U+Y(:
Utility.log(nFileLength); $YSXE :
8z9{H
#{cy(&cz
return nFileLength; @aIgif+v
} 5'zXCHt
}Le]qR9Y]
HlGSt$woX
//保存下载信息（文件指针位置） +,76|oMsQ%
private void write_nPos() `b?uQ\#-M
{ 7UfNz60+~
try{ ZVjB$-do
output = new DataOutputStream(new FileOutputStream(tmpFile)); WXQ@kQD
output.writeInt(nStartPos.length); 7~7L5PRW
for(int i=0;i<nStartPos.length;i++) QN:v4,$d
{ vF72#BNs
// output.writeLong(nPos); w#"\*SKK
output.writeLong(fileSplitterFetch.nStartPos); ^tB1Nu%
output.writeLong(fileSplitterFetch.nEndPos); "aJHCi~l
} UL+Txc
output.close(); 6D;N.wDZ
} -%asHDQ{
catch(IOException e){e.printStackTrace ();} p* >z:=
catch(Exception e){e.printStackTrace ();} QaWS%0go
} 1JJsYX
w~66G
$dL..QH^K
//读取保存的下载信息（文件指针位置） #HUn~r
private void read_nPos() p+d-7'?I
{ x?h/e;
try{ Kj4/fB
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); o<G 9t6~
int nCount = input.readInt(); qN!oN*
nStartPos = new long[nCount]; \x<8
nEndPos = new long[nCount]; g)X3:=['
for(int i=0;i<nStartPos.length;i++) \[MAa:/
{ .~]|gg~
nStartPos = input.readLong(); ]eL# bJ
nEndPos = input.readLong(); fUT[tkb/!
} ?UXFz'
input.close(); dOhSqx56
} +,Eam6g{
catch(IOException e){e.printStackTrace ();} 3lP;=*m.
catch(Exception e){e.printStackTrace ();} 'a~@q~!
} feej'l }F
2dn^K3
\nl(tU#j
private void processErrorCode(int nErrorCode) SI7rTJ]/
{ 3c<aI=$^
System.err.println("Error Code : " + nErrorCode); 78&|^sq
} "5hk%T'
Xaq;d'
hkMeUxS
//停止文件下载 l]*RiK2AC
public void siteStop() 7)Toj
{ r4yz{^G
bStop = true; eM7@!CdA9q
for(int i=0;i<nStartPos.length;i++) f|d~=\0y
fileSplitterFetch.splitterStop(); W`>|OiuF
;:;E|{e
aKI"<%PNn
} y=3 dGOFB
} 1/DtF
//负责部分文件的抓取 j\y;~ V
**FileSplitterFetch.java wi2`5G6|z
*/ ^z?b6kTC
package NetFox; (v]%kXy/G
3?93Pj3oPt
bZu'5+(@
import java.io.*; R"nB4R0Uh
import java.net.*; G%W9?4_K
RY-iFydPc
bC{4a_B
public class FileSplitterFetch extends Thread { WtM%(8Y[]
iq&3S0
ipSMmpB
String sURL; //File URL wuqe{?
long nStartPos; //File Snippet Start Position (NJ{>@&
long nEndPos; //File Snippet End Position 2#wnJdr6E
int nThreadID; //Thread's ID bWe2z~dP
boolean bDownOver = false; //Downing is over ;UdM8+^/V]
boolean bStop = false; //Stop identical B,>02EZ
FileAccessI fileAccessI = null; //File Access interface V DFgu
.LzA'q1+z
vq$6e*A
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `PWKA;W$0
{ J)|3jbX"I]
this.sURL = sURL; 5KCQvv\
this.nStartPos = nStart; s*uA3}j
this.nEndPos = nEnd; MAa9JA8kw)
nThreadID = id; u~uzKG
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Q):#6|u+
} g"-j/ c
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public void run() s:T%,xS
{ !3b& S4
while(nStartPos < nEndPos && !bStop) -&/?&{Q0
{ "x,lL
8ro`lX*F@2
=z1Lim-
try{ ~ #jQFyOh
URL url = new URL(sURL); H%_^Gy8f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); q"d9C)Md
httpConnection.setRequestProperty("User-Agent","NetFox"); 8hGyh#
String sProperty = "bytes="+nStartPos+"-"; y_X6{}Ke
httpConnection.setRequestProperty("RANGE",sProperty); oz!)x\m*H
Utility.log(sProperty); `z!AjAT-G
o;8$#gyNY
=s\$i0A2
InputStream input = httpConnection.getInputStream(); w{ja*F6
//logResponseHead(httpConnection); _){|/Zd
g/GI'8EMj
+k`L8@a3&
byte[] b = new byte[1024]; KzHN|8$o
int nRead; [LVXXjkFI
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) |$WHw*F^
{ j0l,1=^>l
nStartPos += fileAccessI.write(b,0,nRead); 1?'4%>kp
//if(nThreadID == 1) (UkP AE
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pqG>|#RG
} x@#>l8k?
?2@^O=I
jWdviS9&g
Utility.log("Thread " + nThreadID + " is over!"); ;*%rFt9FK
bDownOver = true; %\'=Y/yP
//nPos = fileAccessI.write (b,0,nRead); ;c 7I "?@z
} prJd'
catch(Exception e){e.printStackTrace ();} ne#dEUD
} '|C%X7
} !Dd'*ee-;
. ,|C>^
e@3SF
//打印回应的头信息 !LKxZ"
public void logResponseHead(HttpURLConnection con) Ez1eGPVr
{ 9<mMU:
for(int i=1;;i++) Wn<?_}sa|z
{ A7 RI&g v5
String header=con.getHeaderFieldKey(i); *HrEh;3^J
if(header!=null) }*x1e_m}H
//responseHeaders.put(header,httpConnection.getHeaderField(header)); r8:r}Qj2w[
Utility.log(header+" : "+con.getHeaderField(header)); /?.?1-HM
else p6JTNxD
break; g->*@%?<w>
} Nl\`xl6y]
} =,XCjiBeC
@pH2"k| @
#`Su3~T=S
public void splitterStop() eWH0zswG
{ ^O}a,
bStop = true; tZ]gVgZg
} 0cm34\*
IMM;LC%rD9
#|9W9\f,
} XoN~d
ZU 3Psj
<H-Nft>O
/* kpgvAKyx
**FileAccess.java _S9)<RVI+
*//文件访问(定位，写) 3lF"nv
package NetFox; Nm)3
import java.io.*; q1ysT.{p,
)zL@h
'_v~+
public class FileAccessI implements Serializable{ V%-hP~nyBx
V60L\?a
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Q[OwP
RandomAccessFile oSavedFile; .`D'eS6b
long nPos; ItVN,sVJb
fD!c t;UK
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public FileAccessI() throws IOException c7mKE`
{ lY,^
this("",0); eo+<@83
} f-~Y
~[CFs'`(2
;L-=z]IR,
public FileAccessI(String sName,long nPos) throws IOException 5=o^/Vkc
{ KVZB`c$<t
oSavedFile = new RandomAccessFile(sName,"rw"); <+QdBp'd;
this.nPos = nPos; ZthT('"a
oSavedFile.seek(nPos); JBY.er`6C
} Nh\vWAz9
'rhgM/I
7(@xk_Pl
public synchronized int write(byte[] b,int nStart,int nLen) yTZev|ej@
{ |~Dl<#58
int n = -1; Q}#Je.;
try{ B&cIx~+
oSavedFile.write(b,nStart,nLen); KZKE&bTx
n = nLen; +bumWOQ'
} b 3x|Dq.
catch(IOException e) ^hLr9k
{ _LJF:E5L
e.printStackTrace (); 2yA)SGri
} U[wx){[|
~qinCIj
9c^,v_W@
return n; ~0MpB~ {xd
} =E9\fRGU
j_JY[sex
Tpl]\L1v-
} 0pE>O7
D:T]$<=9
i{^T;uAE
/* K<P d.:
**SiteInfoBean.java QFP9"FM5F
*/ H )ej]DXy
package NetFox; 868X/lL
s%:fZ7y
j[U#J
public class SiteInfoBean { &g|[/~dIr
|62` {+
V'vWz`#
private String sSiteURL; //Site's URL `'1g>Ebk0
private String sFilePath; //Saved File's Path d]DV\*v
private String sFileName; //Saved File's Name |5 V0_79
private int nSplitter; //Count of Splited Downloading File [=K lDfU=
I?rB7*:
[ <X%
public SiteInfoBean() A.>mk598
{//nSplitter的缺省值为5 'rB%a<
//default value of nSplitter is 5 [ U:C62oK,
this("","","",5); JL6$7h
} 4>,X.|9{
GD4S/fn3
NW1Jr/
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) Y-ao yoNS
{ UGAV"0
sSiteURL= sURL; t6"%u3W8M
sFilePath = sPath; C:B7%<
sFileName = sName; |nNcV~%~
this.nSplitter = nSpiltter; Sf?;j{?G
Vuz.b.,i`
=F+v+zP7P
} v~mVf.j1
?+]=|hN
p@jw)xI
public String getSSiteURL() i.mv`u Dm
{ M@ U>@x;
return sSiteURL; OjGI !
} !Se0&Ob
%#2$B+
03~ ADj
public void setSSiteURL(String value) RqA>"[L
{ JLu$1A@ '
sSiteURL = value; rqjq}L)
} g<Z :`00|
R/=rNUe
5m1J&TZ0
public String getSFilePath() OHndZ$'fI
{ 4\n ~
return sFilePath; 3-/|G-4k7
} ]y@A=nR
Da-Lf2qT9
d"XZlEV
public void setSFilePath(String value) t'U=K>7
{ eIvZhi
sFilePath = value; phy}Hk/
} +[G9PP6
qHk{5O3
w~@"r#-
public String getSFileName() W\l&wR
{ <{#_;7h"
return sFileName; H~FI@Cf$L
} 3X gJZ
=mYf] PIX
xSudDhRP
public void setSFileName(String value) Xl4}S"a
{ LhL |ETrJ
sFileName = value; owIpn=8|Q
} fOi Rstci
<&\ng^Z$
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public int getNSplitter() T<n`i~~
{ xX&B&"]5
return nSplitter; uU^DYgs
} y-hTTd"{
>M#@vIo?<6
iM!2m$'s
public void setNSplitter(int nCount) &qbEF3p^@
{ |S!RQ-CF
nSplitter = nCount; ):K%
} ]o'o v
} &GLDoLk6[
Cfi4~&
BdD]HXB|_
/* %r|sb=(yT
**Utility.java t=Oq<r
*/ PaKa bPY
package NetFox; i%o%bib#
9Jwd*gevV
Z:{| ?4
public class Utility { p4P=T@:
> 'R{,1# U
7n5gXiI"
public Utility() 9G[ DuYJI
{ PSJj$bt;<+
&@6xu{o
Ll KO(Q{"
} 4 {M
vm! y2
//线程睡眠 JRB6T_U
public static void sleep(int nSecond) M@T{uo
{ v-#,@&Uwq
try{ )+L|<6JXA
Thread.sleep(nSecond); Gsh9D
} 3S3 a|_+%
catch(Exception e) +<Gp >c
{ MnD}i&k[
e.printStackTrace (); 6_%Cd`4Z
} 7L #)yY
} no+m.B
|Z>-<]p9g
//日志 i"V.$|,
public static void log(String sMsg) )5@P|{FF
{ ZQlk 5
System.err.println(sMsg); 6)1PDlB
} `dm*vd
OkC.e')Vx
vhF9|('G
public static void log(int sMsg) +JI,6)Ry
{ fd4gB6>
System.err.println(sMsg); B :%Vq2`
} 43k'96[2d
} l0'Yq%Nf
i@9 qp?eb
45 ^ Z5t
/* gs1yWnSv5
**TestMethod.java A l;a~45
*/ R([zlw~B5
package NetFox; /%cDX:7X
*Hx*s_F
FF#Aq
public class TestMethod { IFBt#]l0
(wL$h5SG
u0#KBXRo
public TestMethod() (K[e=0Rf
{ ///xx/weblogic60b2_win.exe e\X[\ve
try{ /rpr_Xw}
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ^1){ @(
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =bh: U90y
SiteFileFetch fileFetch = new SiteFileFetch(bean); 1{M?_~g4
fileFetch.start(); y CHOg
} L-- t(G
catch(Exception e){e.printStackTrace ();} r]Hrz'C`
,LwinjHA*
,<Cl^ ^a,
} -,/7u3
0y|1@CS
s O#cJAfuu
public static void main(String[] args) ~2>Adp
{ "81'{\(I_
new TestMethod(); <6;M\:Y*T
} pmP~1=3
} _Yo)m|RaB
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