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)); WBD?|Ss
} He,,bq
for(int i=0;i<nEndPos.length-1;i++) e)= "Fq!
{ ZNVrja*
nEndPos = nStartPos[i+1]; qJ sH
} U9ZuD40\
nEndPos[nEndPos.length-1] = nFileLength; It7R}0Smg
} tr5j<O
} SRtw
k".kbwcaF
uNkJe
//启动子线程 lJ]]FuA-Q
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 'hE'h?-7
for(int i=0;i<nStartPos.length;i++) qA;Gl"HF
{ q{&\nCy
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 0-~s0R89A
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), []v$QR&u#v
nStartPos,nEndPos,i); )s,LFIy<A
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Gx %=&O
fileSplitterFetch.start(); ? cXW\A(
} /IN#1I!K
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 5 w(nttYH
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); HKr}"`I.
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 43x2BW&&
nEndPos = " + nFileLength); Lb)rloca
// fileSplitterFetch[nPos.length-1].start(); 6DU~6c=)
_p>F43%p
,-hbwd~M
//等待子线程结束 n$`+03a
//int count = 0; |p!($
//是否结束while循环 :hT.L3n,
boolean breakWhile = false; e!PB3I
%ufh
"={*0P
while(!bStop) ]J[d8S5
{ S)g:+P
write_nPos(); Fgi`g{N
Utility.sleep(500); }K8e(i6z
breakWhile = true; =[8K#PZ$w
_P=+\[|y
tAE(`ow/Ur
for(int i=0;i<nStartPos.length;i++) m% 3D
{ HdgNy\
if(!fileSplitterFetch.bDownOver) x!fG%o~h
{ "w$,`M?2
breakWhile = false; ?m5EXe
break; *L9v(Kc
} Gbjh|j=
} #CPLvg#
if(breakWhile) 7UY4* j|[C
break; s;YbZ*oaMe
{1Y@%e
od{\z
//count++; 4d%0a%Z
//if(count>4) q8&l%-d`
// siteStop(); %59uR}\
} Rw%% 9
h}!9?:E
5VP0Xa ~
System.err.println("文件下载结束！"); ;}iB9 Tl
} ff5 gE'
catch(Exception e){e.printStackTrace ();} z~X/.>
} F@k}p-e~
9Q^cE\j
qC{JsX`~
//获得文件长度 |ZE^'e*k
public long getFileSize() Db<#gH
{ @J&korU
int nFileLength = -1; X3a9-
try{ 'prHXzi(h
URL url = new URL(siteInfoBean.getSSiteURL()); %0}^M1
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]VxC]a2
httpConnection.setRequestProperty("User-Agent","NetFox"); j{YYG|
z4:<?K
R2n 2mQ<
int responseCode=httpConnection.getResponseCode(); g\fj6
if(responseCode>=400) \7i_2|w
{ ;<N:!$p
processErrorCode(responseCode); m)} 01N4
return -2; //-2 represent access is error uf90
} GkX Se)#p
('SId@
) jH`lY)1
String sHeader; |bz%SB
BaW4 s4u
uZtN,Un
for(int i=1;;i++) pd#Sn+&rf
{ 6_4B!
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 7M~sol[*
//Utility.log(in.readLine()); {='Bd6_=
sHeader=httpConnection.getHeaderFieldKey(i); eFG(2OVg}M
if(sHeader!=null) RzjUrt
{ l>}f{az-T
if(sHeader.equals("Content-Length")) \$ipnQv
{ t$z[ja=
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); ^\AeX-q2v'
break; u30D`sky
} Inv`C,$7Q#
} ?' .AeoE-
else m<hP"j
break; KF00=HE|]
} s91[@rh/
} -1,0hmn=+
catch(IOException e){e.printStackTrace ();} /V:9*C
catch(Exception e){e.printStackTrace ();} [K.1 X=O}
Q}|K29Y:p
,JE_aje7
Utility.log(nFileLength); Q0Ft.b
X)[tb]U/Wx
}a||@unr
return nFileLength; |g)C `k
} d(o=)!p
A}SGw.3
PQkw)D<n]_
//保存下载信息（文件指针位置） ve ysW(z
private void write_nPos() \jtA8o%n
{ 0SQr%:zG
try{ Fs(PVN
output = new DataOutputStream(new FileOutputStream(tmpFile)); Z-Qp9G'
output.writeInt(nStartPos.length); 2Qp}f^
for(int i=0;i<nStartPos.length;i++) ![\-J$
{ N!7}B
// output.writeLong(nPos); iyl i/3|
output.writeLong(fileSplitterFetch.nStartPos); RkYn6
output.writeLong(fileSplitterFetch.nEndPos); 80*hi)ux[
} P[WkW#
output.close(); Gv&G2^
} +QU>D:l
catch(IOException e){e.printStackTrace ();} Sp80xV_B
catch(Exception e){e.printStackTrace ();} E(P 6s;LZ
} FKTF?4+\U
Z5>~l
D#b*M)X"
//读取保存的下载信息（文件指针位置） &2y4k"B&)
private void read_nPos() ::oFL#+
{ w'2FYe{wj
try{ J+`aj8_B
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ixu*@{<Z(
int nCount = input.readInt(); y|}~"^+T
nStartPos = new long[nCount]; !k)6r6
nEndPos = new long[nCount]; /RxP:>hVv
for(int i=0;i<nStartPos.length;i++) '\I(n|\
{ {h@\C|nF
nStartPos = input.readLong(); c4Zpt%:}h
nEndPos = input.readLong(); TwPQ8}pj?
} sQa;l]O:NC
input.close(); [34N/;5
} Cf=H~&`Z
catch(IOException e){e.printStackTrace ();} [i`
catch(Exception e){e.printStackTrace ();} tp] 5[U
} V:kRr cX
Dcvul4Q
tk%f_"}
private void processErrorCode(int nErrorCode) X ."z+-eh
{ m}uOBR+
System.err.println("Error Code : " + nErrorCode); bV8+Eu
} B`B=bn+4
\vAjg
eBrNhE-[G]
//停止文件下载 l(?B0
public void siteStop() etr-\Cp
{ [s>3xWZ+a
bStop = true; >ou=}/<
for(int i=0;i<nStartPos.length;i++) ?{S>%P A_B
fileSplitterFetch.splitterStop(); .>B'oD
<:v+<)K
8%7%[WC#
} @f-X/q]P
} <?nIO
//负责部分文件的抓取 "tz6O0D
**FileSplitterFetch.java \Fz9O-jb4
*/ 8wsU`40=Q
package NetFox; 0>sa{Z
U>E: Ub0r
Jj-\Eb?
import java.io.*; 5?k5J\+
import java.net.*; KNx/1lf
m^D'p
(F4e}hr&
public class FileSplitterFetch extends Thread { xnY?<?J"!
$jN.yNm0
/MF 7ZvN.
String sURL; //File URL o&?c,FwN
long nStartPos; //File Snippet Start Position <b:%o^
long nEndPos; //File Snippet End Position i.Rl&t
int nThreadID; //Thread's ID .11l(M
boolean bDownOver = false; //Downing is over &kg^g%%
boolean bStop = false; //Stop identical _!03;zrO
FileAccessI fileAccessI = null; //File Access interface kv:9Fm\$
0^ODJ7
fu"cX;
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException :,l7e
{ a: "1LnvR
this.sURL = sURL; -+*h'zZ[<w
this.nStartPos = nStart; F^yW3|Sb
this.nEndPos = nEnd; iHD!v7d7
nThreadID = id; 2LwJ%!
fileAccessI = new FileAccessI(sName,nStartPos);//定位 "I.6/9
} h6h6B.\Ld
cE]z Tu?!
=}`d
public void run() E3uu vQ#|
{ Je6[q
while(nStartPos < nEndPos && !bStop) QL/KY G
{ \;{ ]YX
t?GH V3V
d51lTGH7Z
try{ <Vhd4c
URL url = new URL(sURL); 24jf`1XFW
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); W0gS>L_
httpConnection.setRequestProperty("User-Agent","NetFox"); 0'Pjnk-i
String sProperty = "bytes="+nStartPos+"-"; VE )D4RL
httpConnection.setRequestProperty("RANGE",sProperty); Fz7t84g(
Utility.log(sProperty); Q|(}rIWOQA
s6 yvq#:
k~>(XG[x&
InputStream input = httpConnection.getInputStream(); C%o|}iv"
//logResponseHead(httpConnection); WX&IQ@
T~[:oil
\O|SPhaIf
byte[] b = new byte[1024]; 7Jn%XxHq
int nRead; B.8B1MFm
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 6 4_}"fU
{ LDlYLsF9
nStartPos += fileAccessI.write(b,0,nRead); tu -a`h_NJ
//if(nThreadID == 1) #1<m\z7l
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); t+?Bb7p,H
} LDt6<D8,Q
$plk>Khg
B7%,D}
Utility.log("Thread " + nThreadID + " is over!"); ,!:c6F+
bDownOver = true; \*$^}8
//nPos = fileAccessI.write (b,0,nRead); $BwWQ?lp
} hi8q?4jE
catch(Exception e){e.printStackTrace ();} 4Q|>k)H
} <o(;~
} UsE\p9mCuV
FZ-Wgh 0z
=6sP`:
//打印回应的头信息 7[m+r:y
public void logResponseHead(HttpURLConnection con) 0+>g/>
{ `d_T3^ayu
for(int i=1;;i++) T)! }Wvv
{ dSGdK $XA
String header=con.getHeaderFieldKey(i); ]\39#
if(header!=null) #/G!nN #
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ~fXNj-'RW
Utility.log(header+" : "+con.getHeaderField(header)); 1w>[&#7
else y3oq{Z>
break; |J&\/8Q
} -nb U5o
} "hyfo,r
tiK M+ ;C
bQaRl=:[:
public void splitterStop() 6N@=*0kh-
{ *l_a=[<[
bStop = true; '}hSh
} gfL:SP8
/$; Z ~^P
o-<i+To%
} yhH2b:nY(9
uX7L1~s-
c~T{;
/* :w^:Z$-hf
**FileAccess.java :|j[{;asY
*//文件访问(定位，写) ~?/7:S
package NetFox; s\*p|vc
import java.io.*; $xu2ZBK
Zo=,!@q(
4!!|P
public class FileAccessI implements Serializable{ maapX/J
<exCK*G
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 voZaJ2ho/O
RandomAccessFile oSavedFile; k=)U
long nPos; Sm/8VSY
BbB3#/g
Hca(2 ]T-
public FileAccessI() throws IOException !{&r|6
{ x.1=QF{!
this("",0); ZcA"HD%
} :V9Q<B^
N<JI^%HBgP
UN?tn}`!
public FileAccessI(String sName,long nPos) throws IOException D4$b-?y
{ Z_ElLY
oSavedFile = new RandomAccessFile(sName,"rw"); \%r#>8c8
this.nPos = nPos; \KV.lG!
oSavedFile.seek(nPos); &OU.BR>
} rVabkwYD
+C=vuR
I]ej ]46K
public synchronized int write(byte[] b,int nStart,int nLen) L`t786 (M
{ dOD(<
int n = -1; lr&2,p<
try{ AG >D,6Y
oSavedFile.write(b,nStart,nLen); tN{0C/B9
n = nLen; l&H-<Z.8m
} ca=MUm=B
catch(IOException e) .r/s.g
{ (s'xO~p
e.printStackTrace (); P0UR{tK
} &tOo[U?
9^Xndo]y
+9HU&gQ3
return n; {r&r^!K;
} &wNr2PHd#
cJSNV*<
W@}@5,}f>
} R655@|RT
R/{h4/+vJ
.3EEi3z6z
/* eGMw:H
**SiteInfoBean.java (F'~K,0
*/ 2`i&6iz
package NetFox; nu^@}|UG
_3 !s{
]FR#ZvM>x
public class SiteInfoBean { 6?"Gj}|r
7:~3B-Tb
v0'z''KM!
private String sSiteURL; //Site's URL :{w3l O
private String sFilePath; //Saved File's Path I>MLI=[Kg
private String sFileName; //Saved File's Name r[E#JHw
private int nSplitter; //Count of Splited Downloading File ZZi9<g1
E.#JCO|(1
1mV ' ~W
public SiteInfoBean() X'd\b}Bm
{//nSplitter的缺省值为5 NiG&Lw*8
//default value of nSplitter is 5 pTAm}
this("","","",5); UHJro9
} ZV Ko$q:F
ycN!N
PR;Bxy
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ''2:ZXX
{ 6@Q; LV+
sSiteURL= sURL; .WglLUJ:Z
sFilePath = sPath; L<
sFileName = sName; "P5,p"k:)
this.nSplitter = nSpiltter; :Nz TEK
%m|BXyf]_B
B{#Fm6
} ^Oj^7.T+
6heK8*.T
H( LK}[
public String getSSiteURL() dnANlNMk?
{ xfUV'=~(
return sSiteURL; ILG&l<!E
} e23&d
"dG*HKrr
NrcV%-+u%
public void setSSiteURL(String value) lyowH{.N"3
{ $1X!Ecq_
sSiteURL = value; m[ S1
} a;i}<n7
tm;\m!^X{
TPJuS)TU9
public String getSFilePath() uxW |&q
{ $y)tcVc
return sFilePath; %PVu>^
} MDpx@.A,
][f0ZMa
J^kSp
public void setSFilePath(String value) @$b7 eu
{ b#(QZ
sFilePath = value; <{V{2V#
} _)CCD33$
45+kwo0
MNfc1I_#
public String getSFileName() g6q[ I8
{ j1JdG<n
return sFileName; \KEmfCx'n
} 2%l(qfN9
p,4S?cr>a
CyS.GdyP
public void setSFileName(String value) AfW:'>2
{ 'mU\X!- 4<
sFileName = value; =+e;BYD#!
} 9dg+@FS}=
`=TJw,q
S{cK~sZj
public int getNSplitter() 'pAq;2AA
{ Ud-c+, xX
return nSplitter; B)DtJf
} wh]v{Fi'
<.|]%7
-P]onD
public void setNSplitter(int nCount) O|;|7fCB\
{ 6%VRQ#g!
nSplitter = nCount; ]xJ2;{JWsO
} J@Nq
} K>+c2;t;
En+`ZcA\z
}g.)%Bw!
/* ovtZHq/
**Utility.java cMUmJH
*/ P; =,Q$e8
package NetFox; %yy|B
pr"q-S>E
w="
public class Utility { K?wo AuY
4m9]d)
ds+0y;vc
public Utility() =sXk,I;
{ e=6C0fr
#w[Ie+
\T!tUd
} $8_b[~%2
m!<uY?,hf
//线程睡眠 w##$SaTI
public static void sleep(int nSecond) c+TCC%AJQI
{ d_Y7/_i
try{ 5DeAH;
Thread.sleep(nSecond); mVyF M -`
} _`]YWvh
catch(Exception e) K30{Fcb< h
{ 5 .bU2C
e.printStackTrace (); r/ LgmVRn
} \g;-q9g;O
} [M.!7+$o
XuW>GT/
//日志 Pu]Pp`SP
public static void log(String sMsg) n ^C"v6X
{ _E[)_yH'-
System.err.println(sMsg); h1N{;SWQ
} SxRa?5
>]8H@. \
*+cW)klm
public static void log(int sMsg) &14Er,K
{ %,5_]bGvb
System.err.println(sMsg); *p%=u>?&
} 8DJoQl9
} pj'[ H
t'Pn*
=I9RM9O<
/* 7pz #%Hf
**TestMethod.java QK/~lN
*/ FAd4p9[Y
package NetFox; }7|UA%xz
lxD~[e
LZ*ZXFIg
public class TestMethod { ^b`aO$
w ]$Hr
h>'Mh;+
public TestMethod() >*goDtTjp
{ ///xx/weblogic60b2_win.exe %:]ive]e
try{ ]EPFyVt~3
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); nx'D&,VX
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); -]~vEfq+T
SiteFileFetch fileFetch = new SiteFileFetch(bean); f+W%X
fileFetch.start(); {`1gDKH
} PzDekyl
catch(Exception e){e.printStackTrace ();} !@kwHJkv
(\NZ)Ys
OAZ5I)D>
} <MBpV^Y}
-eoXaP{[
a{7'qmN1
public static void main(String[] args) P>i[X0UnL
{ YeCS`IXm
new TestMethod(); s:\FlQ0
} x.~AvJ
} }0~4Z)?e3
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