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)); HON[{Oq
} iDxgAV f*
for(int i=0;i<nEndPos.length-1;i++) .7rsbZzs
{ VQ3&
nEndPos = nStartPos[i+1]; o=2`N2AL
} li XD2N
nEndPos[nEndPos.length-1] = nFileLength; *4VP5]!
} sjkl? _
} 1T?%i
LKY Q?
"G)? E|
//启动子线程 AG0x)
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; *Yjs$'_2
for(int i=0;i<nStartPos.length;i++) [B<{3*R_
{ ]F-6KeBc
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), raZRa*C;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), yYtki
nStartPos,nEndPos,i); EwZt/r
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Di=6.gm[<
fileSplitterFetch.start(); O]!DNN
} Tj+WO6#V
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), w2V E_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); n_2LkW<?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", $&C%C\(>D
nEndPos = " + nFileLength); @V u[Tg}J
// fileSplitterFetch[nPos.length-1].start(); `<Nc Y*
M<7*\1
HWZ*Htr
//等待子线程结束 M$A!
//int count = 0; |(g2fByDf
//是否结束while循环 4D$E
boolean breakWhile = false; Q+N @j]'
Y" |U$
w$HC!
while(!bStop) <[~M|OL9q,
{ IrM3Uh
write_nPos(); gI{F"7fa=
Utility.sleep(500); C`K/ai{4
breakWhile = true; QKQy)g
%LmB`DqZ
GMI>$$<
for(int i=0;i<nStartPos.length;i++) oLRio.u*
{ BpE[9N
if(!fileSplitterFetch.bDownOver) ?2c:|FD
{ Iqv 5lo .
breakWhile = false; D=]P9XDvb.
break; |.yRo_
} AU2Nmf?]%
} CeemR>\t
if(breakWhile) ~8E rl3=5{
break; T]k@g_
tO$M[P=b
``D-pnKK
//count++; ~Q\[b%>J
//if(count>4) 8a1{x(\z.
// siteStop(); 1's^W
} S8t9Ms: k
J)f?x T*
=*N(8j>y
System.err.println("文件下载结束！"); <#i'3TUR
} @ZZ Lh=
catch(Exception e){e.printStackTrace ();} sj2+|>
} p};<l@
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l-rI|0D#
//获得文件长度 I(|{/{P,
public long getFileSize() &[xJfL
{ NU"X*g-x^
int nFileLength = -1; Zs)9OJu
try{ S7]cF5N
URL url = new URL(siteInfoBean.getSSiteURL()); 0jMrL\>C
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Ns{4BM6j
httpConnection.setRequestProperty("User-Agent","NetFox"); 4BX*-t
jkd8M;Jw
N0NMRU]zT
int responseCode=httpConnection.getResponseCode(); PT=%]o]
if(responseCode>=400) HH+XEMP/g
{ {Gy_QRsp,
processErrorCode(responseCode); EhoR.
return -2; //-2 represent access is error UlR7_
} 2t%)d9r32
Gl(,%~F9i
7P]pk=mo
String sHeader; Y|bGd_j
F{S.f1Bsp
`Jo}/c5R
for(int i=1;;i++) z> SCv;Q
{ =Vfj#WL
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Z]dc%>
//Utility.log(in.readLine()); pVM;xxJ
sHeader=httpConnection.getHeaderFieldKey(i); [iz
if(sHeader!=null) ^;e`ZtcI
{ /on p<u
if(sHeader.equals("Content-Length")) Fwtwf{9I
{ dBkB9nz
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Z2r\aZ-d`
break; `1dr$U
} b`' ;`*AN+
} Mmn[ol
else Iq9+
break; +4 dHaj6
} p O.8>C%
} ;6Z?O_zp4
catch(IOException e){e.printStackTrace ();} SJfsFi?n
catch(Exception e){e.printStackTrace ();} Al?XJ C B@
ZWv$K0agu
1=>$c
Utility.log(nFileLength); 5 m:nh<)#
?hO*~w;UU|
E^s>S,U[y
return nFileLength; Hmz[pTQ|87
} *Z(qk`e.b
1*5n}cU~
fw5AZvE6$
//保存下载信息（文件指针位置） s<{c?4T
private void write_nPos() l[gL(p"W
{ 5|Uub,
try{ F+X3CB,f
output = new DataOutputStream(new FileOutputStream(tmpFile)); >2ct1_
output.writeInt(nStartPos.length); c?|/c9f
for(int i=0;i<nStartPos.length;i++) Q{RHW@_/
{ @#p4QEQA
// output.writeLong(nPos); ;:cM^LJ
output.writeLong(fileSplitterFetch.nStartPos); d-4u*>
output.writeLong(fileSplitterFetch.nEndPos); a&&EjI
} *i|hcDk
output.close(); W`KkuQ4cM
} m{X;|-DK[
catch(IOException e){e.printStackTrace ();} W* YfyM
catch(Exception e){e.printStackTrace ();} ;YB8X&H$
} r&#q=R},p
^T"A9uaG
>Kxl+F
//读取保存的下载信息（文件指针位置） K_xn>
private void read_nPos() CZ@M~Si_
{ oR~+s&c
try{ SngV<J>zR
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 0\/7[nwS
int nCount = input.readInt(); /H)l\m +
nStartPos = new long[nCount]; )K}b,X`($
nEndPos = new long[nCount]; cWm.']
for(int i=0;i<nStartPos.length;i++) ]uP{Sj
{ i^=an?}/
nStartPos = input.readLong(); f,$FrI,
nEndPos = input.readLong(); %j'lWwi
} #ws6z`mt
input.close(); REa%kU
} 79&Mc,69
catch(IOException e){e.printStackTrace ();} 6rk/74gI,a
catch(Exception e){e.printStackTrace ();} \]^|IViIQ
} ,y^By_1wS
,5q^/h
Vi]D](^!
private void processErrorCode(int nErrorCode) RD~QNj9,T
{ z*FlZLHY
System.err.println("Error Code : " + nErrorCode); b{(:'.
} Q.nEY6B_
~_K
Dq\#:NnKvx
//停止文件下载 WvR}c
public void siteStop() P0W%30Dh
{ X(bb1
bStop = true; &Zov9o:gx
for(int i=0;i<nStartPos.length;i++) :QN,T3i'/3
fileSplitterFetch.splitterStop(); \4V'NTjB
GU!|J71z
aPWFb.JO4
} [QeKT8
} 7"M7N^
//负责部分文件的抓取 }L@YLnc%
**FileSplitterFetch.java E_$ST3
*/ X!&=S!}
package NetFox; ;DGp7f#9
,u$$w
p<Zf,F}
import java.io.*; rq$%
import java.net.*; |ek*wo
e&E*$G@.7
VGTo$RH
public class FileSplitterFetch extends Thread { b\}`L"
sH6srwI
e7<~[>g)
String sURL; //File URL A=BpB}b
long nStartPos; //File Snippet Start Position 9~a_^m/
long nEndPos; //File Snippet End Position ~]N% {;F}
int nThreadID; //Thread's ID 2PRGwK/
boolean bDownOver = false; //Downing is over ? [=P
boolean bStop = false; //Stop identical ofS9h*wrJ
FileAccessI fileAccessI = null; //File Access interface csYICLj
kD2MqR>
fz<Y9h=
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException _oR6^#5#
{ =#8J9
this.sURL = sURL; NAL%qQ
this.nStartPos = nStart; \@5W&Be^
this.nEndPos = nEnd; $U!w#|&
nThreadID = id; x`a@h\n
fileAccessI = new FileAccessI(sName,nStartPos);//定位 d ;ry!X
} e;Q~P]x
Lc+)#9*d
iTD{
public void run() =PXNg!B}D*
{ I_v]^>Xw
while(nStartPos < nEndPos && !bStop) 8 #0?
{ _QCAV+K'
iPxSVH[
N+h|Ffnp
try{ 6?2/b`k
URL url = new URL(sURL); UGl}=hwKkG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); E|#'u^`yv
httpConnection.setRequestProperty("User-Agent","NetFox"); wtMS<$
String sProperty = "bytes="+nStartPos+"-"; !! #\P7P
httpConnection.setRequestProperty("RANGE",sProperty); 8iq~ha$]|
Utility.log(sProperty); jt?R a1Z
nLYyS#
=n%?oLg^
InputStream input = httpConnection.getInputStream(); ^fH]Rlx
//logResponseHead(httpConnection); ]kc]YO7i%R
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z.#gpTXD
byte[] b = new byte[1024]; \\)3:1X
int nRead; 6VRVk7"
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) #uKHw2N
{ aNfgSo05@n
nStartPos += fileAccessI.write(b,0,nRead); (n#
//if(nThreadID == 1) eDG=-a4
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S tn[M|
} =T;%R^@
^k~{6S,
>pz/wTOi
Utility.log("Thread " + nThreadID + " is over!"); -K+grsb g
bDownOver = true; +STT(bMn
//nPos = fileAccessI.write (b,0,nRead); R0{+Xd
} v^JyVf>
catch(Exception e){e.printStackTrace ();} %J3#4gG^v
} B7va#'ne4{
} _k _F
kf^Wzp
;p1%KmK3
//打印回应的头信息 0A\o8T.12
public void logResponseHead(HttpURLConnection con) 2qw~hWX
{ e(j"u;=
for(int i=1;;i++) iQS?LksQX
{ 6$2)m;| XY
String header=con.getHeaderFieldKey(i); p}N'>+@=
if(header!=null) !j [U
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 3KP6M=
Utility.log(header+" : "+con.getHeaderField(header)); Yr!<O&=
else Z5_MSPm
break; }Li24JK
} ^PO0(rh
} @^/JNtbH!
zI(b#eUF
DS-Kot(k(z
public void splitterStop() <"aPoGda
{ #>[+6y]U!
bStop = true; v-4eN1OS
} SbrBlP:G
liPUK#
^hTq~"
} YgrBIul
'^}l|(
$:F]O$A
/* *m2J$9q
**FileAccess.java N!^U{;X7/
*//文件访问(定位，写) Bglh}_X
package NetFox; RwN*/Li
import java.io.*; bQEQHqY5
866n{lyL
?zKDPBj
public class FileAccessI implements Serializable{ *}cF]8c5W
MZ6?s(mkx
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 '9H]SEw
RandomAccessFile oSavedFile; MX6;ww
long nPos; `fc2vaSH =
T<?JL.8g_
(N0G[(>
public FileAccessI() throws IOException *}A J7]
{ |_ E)2b:h
this("",0); !&ac}uD^g
} M%sWtgw(
=M ?
tb^3-ZUb
public FileAccessI(String sName,long nPos) throws IOException XEY((VL0
{ zEpcJHI%
oSavedFile = new RandomAccessFile(sName,"rw"); 9kQ~)4#
this.nPos = nPos; ,`)!K}2
oSavedFile.seek(nPos); Sh}AGNE'
} eB^:+h#A_
8xZN4ck_@
Z_cTuu0'
public synchronized int write(byte[] b,int nStart,int nLen) m?>$!B4jFB
{ qP*$wKY,
int n = -1; :1s6h%evrT
try{ '72ZLdi}-
oSavedFile.write(b,nStart,nLen); 66Huqo
n = nLen; ?UQE;0 B
} ~g~z"!K
catch(IOException e) VctAQ|h^
{ DpoRR`
e.printStackTrace (); b:WlB[5
} -D`*$rp,
TBvv(_
4Ts5*_
return n; 83Bp_K2\
} ;HgV(d#X
~;3N'o
LezM=om.
} ie=tM'fb
%koHTWT+
iKs/8n
/* V2V^*9(wu@
**SiteInfoBean.java XW%!#S&;X
*/ Cj31'
package NetFox; *3s4JK
Y*dzoN.sW
4-lEo{IIM
public class SiteInfoBean { d {T3
;sS N
YJ_LD6PL9
private String sSiteURL; //Site's URL "fL:scq@0
private String sFilePath; //Saved File's Path th2a'y=0
private String sFileName; //Saved File's Name ZH~T'Bg
private int nSplitter; //Count of Splited Downloading File *U)!9DvA
h7wm xa;
v;80RjPy>
public SiteInfoBean() /~K-0K#w
{//nSplitter的缺省值为5 0Zs}y\J`
//default value of nSplitter is 5 BI3Q~ADV
this("","","",5); uF+if`?
} )?:V5UO\
7eqax33f
(B}+uI{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) |l 03,dOF
{ Q+U}
sSiteURL= sURL; %mAgE\y25
sFilePath = sPath; l+*^P'0u
sFileName = sName; u0Fu_Rtr
this.nSplitter = nSpiltter; pBG(%3PpW
`sAz1/N
x%jJvwb^|
} _}vD?/$L
FQ*4?D,A
9P#E^;L
public String getSSiteURL() _iO,GT=J-
{ =P<gZ-Cm
return sSiteURL; Wt"fn&R}
} A<C`JN}
:lcZ)6&S
g PU|Gv5
public void setSSiteURL(String value) $o?Wum
{ .#2YJ~
sSiteURL = value; pE[ul
} c6:"5};_
8&7LF
35%'HFt_
public String getSFilePath() zZ3,e L
{ I!%T!B540
return sFilePath; Em N0K'x
} Bmm#5X@*
>%h_ R:
%fGS< W;
public void setSFilePath(String value) #joGIw
{ "6Hka{
sFilePath = value; ==F[5]?
} >?ZH[A
h3$.` >l
U N1HBW;
public String getSFileName() : |#Iw
{ q+>J'UGb
return sFileName; AkrUb$ }
} yQ?N*'}$
<.s=)}'`P
/%\E2+6
public void setSFileName(String value) X3NHQMI
{ {w$1_GU
sFileName = value; 7hqa|
} %3M(!X:[
t,4q]Jt
\Lv eZ_h5
public int getNSplitter() lpQsmd#
{ *y9 iuJ}
return nSplitter; rR@ t5
} 6UXa 5t
>:!TfuU^R
rj&
public void setNSplitter(int nCount) qOVs9'R
{ O;h]
nSplitter = nCount; (9]`3^_,J
} ,R5NKWo
} <7fF9X
h7c8K)ntnf
X3vTyIsn
/* uvz}qH@j/Q
**Utility.java V'sp6:3*\
*/ ,'?%z>RZm
package NetFox; 7^P!@o$v!
Pou-AzEP$
>Ip>x!wi
public class Utility { Qctm"g|
=|O`al
`X'-4/Y
public Utility() !Sx}~XB<
{ B.vg2N
:j)H;@[I
S^? @vj
} jFf2( AR
( >zXapb2
//线程睡眠 /bv`_>
public static void sleep(int nSecond) *T' /5,rX2
{ u1s^AW8 y
try{ #m{K
Thread.sleep(nSecond); 12n5{'H2%
} J;,6ydf8!
catch(Exception e) {Hm0Q
{ u;18s-NY
e.printStackTrace (); %wn|H>
} C8>zr6)1
} M/C7<?&
Aq@_^mq1A
//日志 0{#c
public static void log(String sMsg) "vQ$RW -
{ 0|E!e
System.err.println(sMsg); N>!RKf:ir
} "PK\;#[W|
NXb_hF
0l#gS;
public static void log(int sMsg) `W,gYH7
{ 6AV@O
System.err.println(sMsg); KoVy,@
} ]BGWJA5
} 8mI eW
NPc]/n?vDj
L)H'g
/* hn\<'|n
**TestMethod.java j3jf:7 /\
*/ 2V%si6
package NetFox; ${Cb1|g>j
`p1szZD&
Se/VOzzg
public class TestMethod { U\'.rT[#
NKf][!bi
#ak2[UOT
public TestMethod() i lk\&J~I
{ ///xx/weblogic60b2_win.exe 5m{!Rrb
try{ 8##-fv]
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :%cL(',Q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ~`)`Ip
SiteFileFetch fileFetch = new SiteFileFetch(bean); N)|mA)S)
fileFetch.start(); L1ZhH3}X
} yo]!Zn
catch(Exception e){e.printStackTrace ();} %>Z;/j|#r
E/z^~;KA
~H!s{$.5
} '0)a|1,
fQ c%a1'
MUsF/1
public static void main(String[] args) ka? |_(
{ vHSX3\(
new TestMethod(); )\#w=P
} 3`[f<XaL
} mpfc2>6Il.
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