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)); g ypq`F
} ^alZ\!B8
for(int i=0;i<nEndPos.length-1;i++) 2Fgt)`{!
{ +<9 eN
nEndPos = nStartPos[i+1]; ,$zlw\
} BK9x`Oo2
nEndPos[nEndPos.length-1] = nFileLength; '<< ~wt
} Uy5!H1u
} PMhhPw]
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L~y tAZ,
//启动子线程 'h>5&=r
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; puN=OX}C
for(int i=0;i<nStartPos.length;i++) M5WtGIV
{ QhQ"OVFr#
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 8`2<g0V2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ,G|aLBn
nStartPos,nEndPos,i); 6F.7Ws<
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); nDB 2>J
fileSplitterFetch.start(); wZ8 MhE
} kN|5 J
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), B36puz 0{
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); OP`Jc$|6
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ?%/u/*9rj
nEndPos = " + nFileLength); 68<Z\WP
// fileSplitterFetch[nPos.length-1].start(); ~X<cG=p~u
o 7W Kh=
q%k(M[
//等待子线程结束 %m{.l4/!O
//int count = 0; 1"&;1Ts
//是否结束while循环 6$s0-{^
boolean breakWhile = false; H9VXsFTW
|\|)j>[i
``|RO[+2
while(!bStop) dMs||&|&
{ ^qGA!_
write_nPos(); X";ZUp
Utility.sleep(500); 15KV}){
breakWhile = true; M&/aJRBS
wK'!xH^
OssR[$69
for(int i=0;i<nStartPos.length;i++) TT2cOw
{ D"XX920$~
if(!fileSplitterFetch.bDownOver) \!JS7!+
{ !\-4gr?`!
breakWhile = false; KU|BT.o8
break; "WbVCT'i
} g(1B W#$
} -}X?2Q
if(breakWhile) G/z\^Q
break; !3I(4?G,
daB l%a=
mPfUJ#rS
//count++; 1%spzkE 3P
//if(count>4) o9Txo (tYU
// siteStop(); qwF*(pTHq
} Z@,PZ
WVWS7N\
w^])(
System.err.println("文件下载结束！"); qfGtUkSSb
} QGr\I/Y
catch(Exception e){e.printStackTrace ();} 3g0u#t{
} }#OqU# q|
o"#TZB+k
}B=qH7u.K
//获得文件长度 2:iYYRrg
public long getFileSize() |ck ZyDA
{ wD6!#t k
int nFileLength = -1; |O(-CDQe
try{ t1w2u.]
URL url = new URL(siteInfoBean.getSSiteURL()); yS)-&t!;
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); w}j6.r
httpConnection.setRequestProperty("User-Agent","NetFox"); kOAY@a
_}zo /kDA
z$c&=Q
int responseCode=httpConnection.getResponseCode(); gX$0[ sIS.
if(responseCode>=400) qcTmsMpj
{ c.(Ud`jc
processErrorCode(responseCode); Zj1ZU[BEcL
return -2; //-2 represent access is error J3~hzgY
} f2 ydL/M,
0L:V#y-*
22GnbA7O
String sHeader; =! N _^cb
to&N22a$
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for(int i=1;;i++) lk_s!<ni
{ X'FEOF
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); .]j#y9>&w%
//Utility.log(in.readLine()); `10X5V@hP
sHeader=httpConnection.getHeaderFieldKey(i); E kBae=
if(sHeader!=null) qRPc%"
{ /&]-I$G@
if(sHeader.equals("Content-Length")) >*`>0Q4y
{ ?dsf@\
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 3>Q@r>c
break; ADYx.8M|9i
} jby~AJf%
} /M^V2=
else 'Aj(i/CM
break; [jl2\3*
} X`yNR;>
} .!JMPf"QEI
catch(IOException e){e.printStackTrace ();} 3(!/["@7
catch(Exception e){e.printStackTrace ();} IXZ(]&we
Vk-W8[W 7
~reQV6oQua
Utility.log(nFileLength); -F"d0a,
G{kj}>kS_
uxa=KM1H
return nFileLength; ,`<^F:xl
} \|2tTvW,0
8 7RHA $?
Y*@|My`
//保存下载信息（文件指针位置） rIeM+h7Wn
private void write_nPos() 61/)l0<;
{ Hp\Ddx >Jd
try{ V@vhj R4r\
output = new DataOutputStream(new FileOutputStream(tmpFile)); m[Z6VHn
output.writeInt(nStartPos.length); uR#'lb`3
for(int i=0;i<nStartPos.length;i++) IQ3n@
{ .OmQ'
// output.writeLong(nPos); ?k{|Lk
output.writeLong(fileSplitterFetch.nStartPos); gyi)T?uS)
output.writeLong(fileSplitterFetch.nEndPos); @Q;i.u{V
} P*pbwV#|
output.close(); r\(v+cd
} S:ls[9G[3
catch(IOException e){e.printStackTrace ();} 9i0M/vx
catch(Exception e){e.printStackTrace ();} =op`fn%
} tC&fAE:S
u3]Uxy
[{`)j
//读取保存的下载信息（文件指针位置） p?Ed- S
private void read_nPos() sFLcOPj-%
{ Hqvc7-c6
try{ >b>MKm>q
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); NEA_Plt
int nCount = input.readInt(); 79D=d'eA
nStartPos = new long[nCount]; E{uf\Fc
nEndPos = new long[nCount]; !w q4EV
for(int i=0;i<nStartPos.length;i++) i90}Xyt
{ Q[M (Wqg
nStartPos = input.readLong(); (lb6]MtTHY
nEndPos = input.readLong(); R6`*4zS
} 0$tjNye
input.close(); Mx8Gu^FW.d
} On=u#DxQ
catch(IOException e){e.printStackTrace ();} DU;[btK>
catch(Exception e){e.printStackTrace ();} h$70H^r
} 9b1?W?"
<B!'3C(P
##H;Yb
private void processErrorCode(int nErrorCode) =HVfJ"vK
{ R|iEvt
System.err.println("Error Code : " + nErrorCode); &K>cW$h=a
} +UzXN$73
-'6<
&i5:)d]L
//停止文件下载 ~n WsP}`n
public void siteStop() || [89G
{ %JQ~!3
bStop = true; 6/| 0+G^
for(int i=0;i<nStartPos.length;i++) 6O9iEc,HM
fileSplitterFetch.splitterStop(); z!$gVWG
mj@31YW
XYjcJ
} 4r\*@rq
} ~\$=w10
//负责部分文件的抓取 Jen%}\
**FileSplitterFetch.java PWvSbn6
*/ D9.`hs0
package NetFox; QC{u|
mzGjRl=O
1?(cmXj
import java.io.*; *(G&B\
import java.net.*; 4QE=f(u;h
r} Lb3`'
/HkFlfPd
public class FileSplitterFetch extends Thread { bni)Qw
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g<$. - g
String sURL; //File URL vt.P*Z5
long nStartPos; //File Snippet Start Position }taLk@T
long nEndPos; //File Snippet End Position Q"%S~&#'
int nThreadID; //Thread's ID qe$33f*
boolean bDownOver = false; //Downing is over j$Nf%V 6Y
boolean bStop = false; //Stop identical ~wOTjz
FileAccessI fileAccessI = null; //File Access interface MTb,Kmw<(
1AF%-<`?s
d",(aZ
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException d ;^
{ n!G.At'JP
this.sURL = sURL; |O-`5_z$r
this.nStartPos = nStart; w9f _b3
this.nEndPos = nEnd; hGI+:Js6
nThreadID = id; yHNuU)Ft
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7X}TB\N1
} ]]TqP{H
wiJRCH
$W&:(&
public void run() vT c7an6fy
{ YLOwQj'
while(nStartPos < nEndPos && !bStop) l4vTU=
{ 4(=kE>n}
oQT2S>cm^
E1 |<Pt
try{ "_< 9PM1t
URL url = new URL(sURL); X*F_<0RC1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cJDd0(tD!
httpConnection.setRequestProperty("User-Agent","NetFox"); *}cSE|S%
String sProperty = "bytes="+nStartPos+"-"; 7+nm31,<O
httpConnection.setRequestProperty("RANGE",sProperty); >{5 p0
Utility.log(sProperty); \\:|Odd
+;Cr];b3
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InputStream input = httpConnection.getInputStream(); V}" g~=
//logResponseHead(httpConnection); ;+U<bqL6
0{+.H_f`
M:|8]y@
byte[] b = new byte[1024]; /=)L_
int nRead; gKo%(6{n~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) a460|w6
{ 7Xg?U'X
nStartPos += fileAccessI.write(b,0,nRead); WC*=rWRxF
//if(nThreadID == 1) rrqQCn9
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Wd8Ru/
} Gb2L }
6L9,'Bg
*k [J6
Utility.log("Thread " + nThreadID + " is over!"); yZCX S
bDownOver = true; &Z;_TN9[
//nPos = fileAccessI.write (b,0,nRead); T95t"g?p
} W.I\J<=V
catch(Exception e){e.printStackTrace ();} dNiH|-$an
} |3shc,7
} bgF^(T35
BRS#Fl:
O_;Dk W
//打印回应的头信息 SZhOm
public void logResponseHead(HttpURLConnection con) h Dk)Qg
{ !GwL,)0@^
for(int i=1;;i++) -Z0+oU(?YE
{ L',mKOej
String header=con.getHeaderFieldKey(i); *?t%0){
if(header!=null) V'DA[{\*
//responseHeaders.put(header,httpConnection.getHeaderField(header)); UZ2TqR
Utility.log(header+" : "+con.getHeaderField(header)); MHi8E9_O
else )Si2u5
break; YKZa$@fA?
} @1-F^G%p8
} z6*<V5<7
3jZ6kfj
`P}9i@C
public void splitterStop() $}GTG'*.
{ F;q#&
bStop = true; Kibr ]w
} a5jL7a?6]
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o!c] (
} ?K_ '@
*\G)z|^yx
0bS|fMgc
/* :A1:
**FileAccess.java @-&MA)SN
*//文件访问(定位，写) T-_"|-k}P%
package NetFox; =(HeF.!
import java.io.*; c>:R3^\lwx
bBc[bc>R
`aC){&AP(
public class FileAccessI implements Serializable{ . pzC5Ah
z (?=Iv3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 m ci/'b Xt
RandomAccessFile oSavedFile; O%8EZyu
long nPos; "N?+VkZEv
u #w29Pm
(kv?33
public FileAccessI() throws IOException _)T5lEFl=
{ J aTp}#
this("",0); S!v(+|
} <{5EdX
'Ft0Ry<OL
q 11IkDa
public FileAccessI(String sName,long nPos) throws IOException )3Z ^h<"j
{ HlvuW(,x=
oSavedFile = new RandomAccessFile(sName,"rw"); RTh`ENCKR
this.nPos = nPos; <r#eL39I
oSavedFile.seek(nPos); Vw||!d
} m,UGWR
:a ->0 l
6 5N~0t
public synchronized int write(byte[] b,int nStart,int nLen) #X 52/8G
{ j)C,%Ol
int n = -1; H,nec<Jp
try{ o%9*B%HO/
oSavedFile.write(b,nStart,nLen); d?`ny#,GB
n = nLen; aE;le{|!({
} scLn=
catch(IOException e) fC,:{}
{ t3(]YgF
e.printStackTrace (); J &pO%Q=b
} FCi U
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2EZb )&Q
return n; Y2o?gug
} $6OkIP.
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ojyIQk+
} S"wR%\NIp
7(5xL T$
pn.wud}R
/* a,2'+Tlo
**SiteInfoBean.java 8V^oP]Y
*/ =6"2UC&
package NetFox; X/iT)R]b
EQ'V{PIfj
?7<JQh)"e
public class SiteInfoBean { Zjbc3M5
3)\8%Ox
MrZh09y
private String sSiteURL; //Site's URL t2,A@2DU2
private String sFilePath; //Saved File's Path UfN&v >8f
private String sFileName; //Saved File's Name KMI_zhyB
private int nSplitter; //Count of Splited Downloading File 0"CG7Vg,zh
^*P%=>zO
&|f@$ff
public SiteInfoBean() 8GvJ0Jq}U
{//nSplitter的缺省值为5 rM'=_nmi
//default value of nSplitter is 5 xx[9~z=d
this("","","",5); ZI=%JU(
} sCR67/
=c/wplv*
}ZYv~E'
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) fQ#l3@in
{ Z?wU
sSiteURL= sURL; e,t(q(L
sFilePath = sPath; (M*FIX
sFileName = sName; U}[I
this.nSplitter = nSpiltter; 5$V_Hj
^h69Kr#d4
0NS<?p~_S
} bbrXgQ`s+w
l c+g&f
9FB19
public String getSSiteURL() -r-k_6QP
{ ^J$2?!~
return sSiteURL; R8ZK]5{o
} spt6]"Ni
KXx32 b,~
0g+'/+Ho 4
public void setSSiteURL(String value) q@[QjGj@
{ Y;?{|
sSiteURL = value; _lamn}(x0
} V5UF3'3;}
["h5!vj
9I&xfvD,
public String getSFilePath() nih0t^m'
{ 19w*!FGX
return sFilePath; 7Zlw^'q$:L
} wK?vPS
Tj:B!>>
R}O_[
public void setSFilePath(String value) $<}$DH_Y
{ tfj:@Z5&$C
sFilePath = value; P-?0zF/T$
} &J+CSv,39
wne,e's}
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public String getSFileName() Xu%'Z".>:
{ wOU_*uY@6'
return sFileName; ML|FQ
} f&Gt|
}H^+A77v
KV(Q;~8"X
public void setSFileName(String value) >CHrg]9
{ lhy*h_>
sFileName = value; ?l9XAWt\
} D]zwl@sRX:
nAv#?1cjz
?8'*,bK
public int getNSplitter() 'uBu6G
{ 4y|BOVl
return nSplitter; $g>IyT[
} aAD^^l#
]n6#VTz*
]s<[D$ <,
public void setNSplitter(int nCount) t'n pG}`tE
{ -XB/lnG
nSplitter = nCount; A^USBv+9`
} JMC. w!
} fp`;U_-&0
;ub;lh3
+S o4rA*9
/* Ayxkv)%:@)
**Utility.java uXn1 'K<'2
*/ uvkz'R=
package NetFox; b3=rG(0f
8A##\j)
vS;RJg=
public class Utility { %)1y AdG 8
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v[1aWv:
public Utility() Kp%2k^U
{ G<65H+)M\
>qnko9V
wW>A_{Y
} d;boIP`M;
s6 uG`F"
//线程睡眠 ztcp/1jIvS
public static void sleep(int nSecond) jeoz*Dz
{ (C\]-E>
try{ f6hnTbJ
Thread.sleep(nSecond); +$ 'Zf0U
} &u$Q4
catch(Exception e) E(>=rD/+
{ P3x8UR=fS
e.printStackTrace (); NG+GEqx
} "L IF.)
} 9ijfRqI=x
3lrT3a3vV
//日志 11Q1AN
public static void log(String sMsg) Ag-(5:
{ 8\&X2[oAD
System.err.println(sMsg); fK>L!=Q
} 1m4$p2j
~!B\(@GU
'OITI TM
public static void log(int sMsg) -*1d!
{ f,U.7E
System.err.println(sMsg); UXJeAE-
} &*M!lxDN
} "q3ZWNS'w
K@ I9^b
(S>C#A=E\
/* ,0M_Bk"
**TestMethod.java V(H1q`ao9
*/ o_izl\
package NetFox; 03$mYS_?
R`NYEptJ
KLST\Ln:
public class TestMethod { B6MB48#0gs
T6\[iJI|
(nQ^
public TestMethod() p$S*dr
{ ///xx/weblogic60b2_win.exe ;AG8C#_
try{ .]8ZwAs=&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); d[iQ`YW5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); bV^rsJm
SiteFileFetch fileFetch = new SiteFileFetch(bean); qU \w=
fileFetch.start(); Q*D;U[
} qqjwJ!@P
catch(Exception e){e.printStackTrace ();} `+]Qz =}
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4>wP7`/+y
} R$R*'l
!z\h|wU+
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public static void main(String[] args) yuh *
{ <$D`Z-6
new TestMethod(); 8?xE6
} )W^F2-{
} ju8>:y8
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