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)); h[I~D`q)v
} *S=zJyAO
for(int i=0;i<nEndPos.length-1;i++) v6`TbIq%
{ #&ZwQw
nEndPos = nStartPos[i+1]; ([L5i&DT
} 0'4V*Y
nEndPos[nEndPos.length-1] = nFileLength; {9*k \d/;
} @`Foy
} 7Q3a0`Iq
Fb9!x/$tGV
x6={)tj
//启动子线程 !`?*zf
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; [agp06 $D?
for(int i=0;i<nStartPos.length;i++) Q7@.WG5
{ o$+"{3svw?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), $M 1/74
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), T`.RP&2/d
nStartPos,nEndPos,i); p8a\> {
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); @80Z@Pj
fileSplitterFetch.start(); 2[R{IV8e
} i?1g{JW
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Pf?y!dK<
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ^&6'FE
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", \<K@t=/ 6
nEndPos = " + nFileLength); E||[(l,b
// fileSplitterFetch[nPos.length-1].start(); c>nXnN
NRgNW1#
rYYAZ(\8
//等待子线程结束 j[<}l&
//int count = 0; }D>nXhO&
//是否结束while循环 1JXa/f+
boolean breakWhile = false; Q]d3a+dK
^q=D!g
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while(!bStop) llP 5
{ =UW! 7OzC
write_nPos(); t^zmvPDK
Utility.sleep(500); %d/Pc4gfc
breakWhile = true; pk0Cx
HKZD*E((
7$&3(#!N
for(int i=0;i<nStartPos.length;i++) N?mTAF'M
{ KixS)sG
if(!fileSplitterFetch.bDownOver) r|>a;nY
{ g1s\6%g
breakWhile = false; N-4k 9l1
break; *.]M1
} b7_uT`<
} >uN)O-
if(breakWhile) rG*Zp7{
break; >u:t2DxE
%8a886;2
&58+-jzW
//count++; . w_oWmD
//if(count>4) F qW[L>M'
// siteStop(); R|Lr@k{6+r
} 05cyWg9a
- s,M+Q(<
U3f a*D
System.err.println("文件下载结束！"); ]%y3*N@AZ
} &>m# "A\^
catch(Exception e){e.printStackTrace ();} >5Rcj(-&l
} XJG"Zr9
] 3@.)
<-1(G1v
//获得文件长度 0*F{=X~L
public long getFileSize() x!08FL)
{ F.0CJ7s
int nFileLength = -1; Gz9w1[t
try{ `N69xAiy
URL url = new URL(siteInfoBean.getSSiteURL()); Ikn)XZU^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [?vn>
httpConnection.setRequestProperty("User-Agent","NetFox"); 7z=zJ4C
3. kP,
gfPht 5
int responseCode=httpConnection.getResponseCode(); y.l`NTT]<
if(responseCode>=400) "#a_--"k9
{ t)*MLg<C
processErrorCode(responseCode); R\B-cU[,
return -2; //-2 represent access is error nf7l}^/UE
} lStYfO:<'v
JQhw>H9&
"|6#n34
String sHeader; U?}>A5H
^" EsBt
KAucSd`
for(int i=1;;i++) jJxV)AIY
{ pS3TD"p
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 8U5L|Ny.q
//Utility.log(in.readLine()); \[Dxg`;4
sHeader=httpConnection.getHeaderFieldKey(i); IU8/B+hM~
if(sHeader!=null) $H9+>Z0(
{ >Bj+!)96q
if(sHeader.equals("Content-Length")) _djr>C=H"
{ oTPPYi[r
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); 1,tM
break; YtzB/q8I
} ptrQ~m-
} TfYXF`d
else K9#=@}!3L
break; }T}9AQ}|
} `Eijy3>h
} Tw!]N%E
catch(IOException e){e.printStackTrace ();} \UdHN=A&
catch(Exception e){e.printStackTrace ();} UUf-G0/P
nnV(MB4z1
Y 7a<3>
Utility.log(nFileLength); SOq{`~,4B
I?l%RdGW
Jv|uI1V
return nFileLength; S+d@RMdes
} 0jlwL
thYG1Cs
E0miX)AG
//保存下载信息（文件指针位置） H>x(c|ZBp
private void write_nPos() .KA){_jBp
{ #sn2Vmi
try{ !f\q0Gnl
output = new DataOutputStream(new FileOutputStream(tmpFile)); SA| AS<
output.writeInt(nStartPos.length); J;K-Pv+
for(int i=0;i<nStartPos.length;i++) Fo=hL
{ "pDwN$c
// output.writeLong(nPos); 'Y ZYRFWXM
output.writeLong(fileSplitterFetch.nStartPos); FY^[?lj
output.writeLong(fileSplitterFetch.nEndPos); dU7+rc2,CU
} h@5mVTb}i
output.close(); TsPx"+>7`
} ^r u1QDT
catch(IOException e){e.printStackTrace ();} fgs){Ng`
catch(Exception e){e.printStackTrace ();} 8| 6:
} yA8e"$
/.'tfy$
s<i& q {r
//读取保存的下载信息（文件指针位置） 8E m X
private void read_nPos() `h>a2
{ Q -!,yCu
try{ u}eqU%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); y5d=r]_S:
int nCount = input.readInt(); HAHv^
nStartPos = new long[nCount]; Oie0cz:>:
nEndPos = new long[nCount]; Mpfdl65
for(int i=0;i<nStartPos.length;i++) T ~9)0A"]
{ S1iF1X(+?X
nStartPos = input.readLong(); pZS0;T]W,
nEndPos = input.readLong(); ZeUA e
} 03WLVP@
input.close(); ewNzRH,b
} nN=o/zd
catch(IOException e){e.printStackTrace ();} "k)}qI{
catch(Exception e){e.printStackTrace ();} ?R 4sH
} 4,8=0[eRG
h|=<I)}z
X=i^[?C
private void processErrorCode(int nErrorCode) qUH02"z@9
{ YEL,TU
System.err.println("Error Code : " + nErrorCode); PdUlwT?8C
} (v11;kdJB
p)5j~Nl
W| z djb
//停止文件下载 1Na*7|
public void siteStop() i8F^ N=
{ kZ&|.q1zki
bStop = true; Z/#&c
for(int i=0;i<nStartPos.length;i++) v99gI%TA'
fileSplitterFetch.splitterStop(); .?L&k|wX-
.eg?FB'7
C #A sA
} $\S;f"IM.
} .AIlv^:|U
//负责部分文件的抓取 Htg,^d 5
**FileSplitterFetch.java O]"3o,/]G
*/ =J2\"6BnzA
package NetFox; :ET05MFs\#
}:5_vH0
Pc+8CuN?
import java.io.*; :[;]6;
import java.net.*; 1o&]=(
&+@~;p5F
X@;o<2^
public class FileSplitterFetch extends Thread { v8 Q/DJ~
MIblx
,/d R
String sURL; //File URL ' }G!D
long nStartPos; //File Snippet Start Position W'3&\}
long nEndPos; //File Snippet End Position [I4:R_\
int nThreadID; //Thread's ID ]}KoW?M
boolean bDownOver = false; //Downing is over aR3R,6ec
boolean bStop = false; //Stop identical av-l_iE
FileAccessI fileAccessI = null; //File Access interface {s=n "*Qp)
s:_M+_7_
2~:jg1
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException E5-f{Qc
{ v9<7=D&x
this.sURL = sURL; 8db J'
this.nStartPos = nStart; f L @rv
this.nEndPos = nEnd; K+9oV[DMs
nThreadID = id; .AEOf0t
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ZG=B'4W
} X67.%>#3
]}4{|& e
_R&}CP
public void run() !ke_?+8sY
{ wzLR]<6G
while(nStartPos < nEndPos && !bStop) v35wlt^}
{ wYZ"fusT
%9D$N
<AZ21"oR/
try{ G#V}9l8Q
URL url = new URL(sURL); 64qm
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W/z\j/Rgc
httpConnection.setRequestProperty("User-Agent","NetFox"); oV4+w_rrLc
String sProperty = "bytes="+nStartPos+"-"; S >E|A%
httpConnection.setRequestProperty("RANGE",sProperty); Y)?dq(
Utility.log(sProperty); "`b"PQ<x
I6bekOvP
G8c 8`~t
InputStream input = httpConnection.getInputStream(); 7@[3]c<=
//logResponseHead(httpConnection); %9|}H [x
p&B c<+3e
a&>Tk%
byte[] b = new byte[1024]; .C]V==z`[4
int nRead; 2k\i/i/Y
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3j{VpacZY
{ 9fk@C/$
nStartPos += fileAccessI.write(b,0,nRead); #[.vfG
//if(nThreadID == 1) tBDaFB
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); w]Q0}Z
} ]dZ8]I<$C
$"P9I-\m
[ \I&/?On
Utility.log("Thread " + nThreadID + " is over!"); ,vfi]_PK
bDownOver = true; E0K'|*
//nPos = fileAccessI.write (b,0,nRead); <E2+P,Lgw
} P4"Pb\o*
catch(Exception e){e.printStackTrace ();} B7:8%r/
} %GRD3S
} |aH;@V
=@#[@Ia
%O5 k+~9
//打印回应的头信息 yo)a_rY
public void logResponseHead(HttpURLConnection con) uZsm=('ww
{ T*,kBJ
for(int i=1;;i++) ,|gX?[o
{ F_8nxQ-
String header=con.getHeaderFieldKey(i); EJ$-
if(header!=null) ML6V,V/e
//responseHeaders.put(header,httpConnection.getHeaderField(header)); DNsDEU
Utility.log(header+" : "+con.getHeaderField(header)); +xqPyR
else (p1y/"Xh
break; w7b?ve3-
} W"9?D
} _pu G?p
y %dUry%>
zWiMl.[
public void splitterStop() ld~8g,
{ :e-&,K
bStop = true; .@0i,7S
} Dq/ _#&S
d*%-r2K
L8<Yk`jx
} TNs0^h)
P8DT2|Z6f]
2ql7*g?Uq@
/* jEQr{X7bEL
**FileAccess.java ,E]u[7A
*//文件访问(定位，写) %|(~k*s4
package NetFox; $y!k)"k
import java.io.*; NB]T~_?]*
^%X,Rml<e
lk $S"OH!
public class FileAccessI implements Serializable{ &FrW(>2
;IhkGPpWP
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Fs q=u-= :
RandomAccessFile oSavedFile; QJFx/zU
long nPos; .lMIJN&/
zh5{t0E}C
76[O3%
public FileAccessI() throws IOException Hu$]V*rAG
{ >S /Zd
this("",0); &*TwEN^h
} du2q6"
@;>TmLs
uVoM2n?D%^
public FileAccessI(String sName,long nPos) throws IOException 5MJ`B:He+
{ w7Nb+/,sg
oSavedFile = new RandomAccessFile(sName,"rw"); .Z=D|&!
this.nPos = nPos; WeGT}
oSavedFile.seek(nPos); L]{ 1"`#
} A8JEig 3Ix
7p""5hw
s&S8P;K|
public synchronized int write(byte[] b,int nStart,int nLen) `Q!|/B
{ ;^)(q<]
int n = -1; 5m")GWQaP@
try{ p#}38`
oSavedFile.write(b,nStart,nLen); l[]K5?AS>-
n = nLen; ;EP]A3
} @F_#d)+%>
catch(IOException e) Q2;zve&Dl
{ n50XGv
e.printStackTrace (); v'`9^3(-
} 5q[0;`J
q_Td!?2?
2Up1 FFRx
return n; Fy-+? ~
} Y7R"~IA$
|xaJv:96%
Mf0g)X}1
} T:Dp+m!\{
'tK5s>gv<
se](hu~w
/* ;czMsHu0X
**SiteInfoBean.java iqCKVo7:M
*/ hx$-d}W{
package NetFox; o"@y=n/
}'{39vc .
P>%\pCJ])
public class SiteInfoBean { H`4H(KWm
Oqzz9+
T{M~*5$
private String sSiteURL; //Site's URL 2U,O e9
private String sFilePath; //Saved File's Path G.K3'^_
private String sFileName; //Saved File's Name | ]`gps
private int nSplitter; //Count of Splited Downloading File U6qv8*~
uAT01ZEm
,)A^3Q*
public SiteInfoBean() Fz7(Kuc
{//nSplitter的缺省值为5 [X:mmM0gd
//default value of nSplitter is 5 FKflN
this("","","",5); yn<z!z%mz
} ;J pdnV
UD[S>{
10dVV[=
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) +F ~;Q$T
{ uf,4GPo,
sSiteURL= sURL; N$J)Ow
sFilePath = sPath; T{u!4Yu
sFileName = sName; wL,b.]
this.nSplitter = nSpiltter; ^GdU$%aa
}NPF]P;
We3*WsX\
} Iw~3y{\
Y?hC/6$7
p2|c8n==
public String getSSiteURL() B?c9cS5Mj
{ ITh1|yP
return sSiteURL; haW8zb0z
} z<rdxn,9
}gL9G
wzB*M}3
public void setSSiteURL(String value) S4kGy}{+i
{ RsU=fe,
sSiteURL = value; +uW$/_Y$
} &NV[)6!
E!'H,#"P
J) v~
public String getSFilePath() _#9:cH*
{ 0~RsdQGqC
return sFilePath; U7J0&
} KC o<%
Y-&r_s_~
,s0E]](
public void setSFilePath(String value) %[4/UD=7
{ i](,s.
sFilePath = value; Ojp)OeF\
} DR/qe0D
u3kK!2cdP
G5Y5_r6Gu
public String getSFileName() o7VNw8Bp
{ YKLh$
return sFileName; 12Qcjj%F*
} LU4\&fd
5bFE;Y;
*=0Wh@?0
public void setSFileName(String value) PEZElB;
{ ayyn6a8
sFileName = value; A|tee@H*0
} "xZ]i)
$*K5
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public int getNSplitter() |x["fWK
{ =<(:5ive
return nSplitter; C1P{4 U
} 7P9n. [
1Nw&Z0MI
?UQVmE&
public void setNSplitter(int nCount) y|q4d(P.
{ d9|dHJf
nSplitter = nCount; 6BVV2j)zl:
} .%`|vGF
} )7=B]{B_
P]T(I/\g
X`]-)(UX
/* FQB)rxP
**Utility.java BDxrSq,H
*/ 2F^ %d9`
package NetFox; ;6t>!2I>C
;_K+b,
%f\{ ]
public class Utility { GmtMA|
2.}<VivT
`3kE$h#
public Utility() ]R}#3(]1
{ Ri4_zb
UT [7 J
m\7-/e2a
} hxx,E>k
O+`^]D7
//线程睡眠 #`:s:bwM:
public static void sleep(int nSecond) 2ko7t9y&
{ *jGB/ y
try{ C!XI0d
Thread.sleep(nSecond); x+|Fw d
} PqPLy
catch(Exception e) "%urT/Fv&
{ %H>vMR-,~
e.printStackTrace (); /V~L:0%
} P~_CDh.N
} 0{v?
9 f-T>}
//日志 swG^L$r`
public static void log(String sMsg) xj{X#[q):
{ "Na9Xea
System.err.println(sMsg); v6oPAqj,r
} riZFcVsB
G6JyAC9j
VbM5]UT/
public static void log(int sMsg) /}2 bsiJT
{ 0NfO|l7P
System.err.println(sMsg); )]J I Q"rR
} ,.]e~O4R
} Y:^ =jV7
!W^2?pqN
_4o2AS:j
/* kR^7Z7+#*
**TestMethod.java Y@KZ:0<
*/ nX5*pTfjL3
package NetFox; &Xe r#6~
tA#X@HIE
(&PamsV*8
public class TestMethod { 'nP'MA9b;a
^K@r!)We
vbqI$F[s
public TestMethod() w?C_LP
{ ///xx/weblogic60b2_win.exe )g:UH Ns
try{ [2 2IF
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ="@W)"r
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); =d~]*[8
SiteFileFetch fileFetch = new SiteFileFetch(bean); ifTVTd7O
fileFetch.start(); |rdG+>
} &-<"HW
catch(Exception e){e.printStackTrace ();} wuzz Wq
}K~JM1(26
aZ@4Z=LK
} s%GiM
68FxM#xR
6xdu}l=%
public static void main(String[] args) "1%<IqpU+
{ -J[zJ4z#
new TestMethod(); *^Zt5 zk
} t8i"f L
} gywI@QD%#
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