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)); M;-PrJdyt
} <V>]-bl/
for(int i=0;i<nEndPos.length-1;i++) /Rf:Z.L
{ =YOq0
nEndPos = nStartPos[i+1]; Y2W|b5
} xo a1='
nEndPos[nEndPos.length-1] = nFileLength; b<n*wH
} mA@FJK_
} xG/B$DLn
_h6SW2:z!E
d)1 d0ES
//启动子线程 .J"QW~g^
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =;ClOy9
for(int i=0;i<nStartPos.length;i++) s'b 4Me
{ u%!/-&?wF
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), qHaH=g%
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ^CO{86V
nStartPos,nEndPos,i); 0Ta&o-e
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9sG]Q[:.]
fileSplitterFetch.start(); G5vp(%j
} d<K2 \:P{}
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), #9zpJ\E
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :y'EIf
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Xdh2
nEndPos = " + nFileLength); `Y O(C<r-
// fileSplitterFetch[nPos.length-1].start(); g&z8t;@
l0 =[MXM4
/9ctmW1!<
//等待子线程结束 6~c#G{kc
//int count = 0; h?[|1.lJx(
//是否结束while循环 2Pow-o*r
boolean breakWhile = false; }D>#AFs6#
7-:R{&3Lm:
)Zf1%h~0r
while(!bStop) I+=+ ,iXhB
{ V'hb 4}@
write_nPos(); &S,_Z/BS;
Utility.sleep(500); <Pzy'9
breakWhile = true; `AYq,3V
vd?Bk_d9k,
DA1?M'N
for(int i=0;i<nStartPos.length;i++) .7]P-]uOZ
{ o?Aj6fNY?
if(!fileSplitterFetch.bDownOver) H2H`7 +I,
{ *Nm$b+
breakWhile = false; Mg#yl\v
break; 4-~Z{#-
} SQ_Je+X
} Q$uv \h;
if(breakWhile) Kci. ,I
break; G54J'*Z
gg>QXui
(+c1.h
//count++; ],_+J*
//if(count>4) dvZH~mF
// siteStop(); (:aU"5M
} AtewC Yo
D|)a7_
~wa6S?
System.err.println("文件下载结束！"); QF)\\D[
} P#O2MiG
catch(Exception e){e.printStackTrace ();} f(Y_<%
} /a'1W/^2
N0H=;CIQ
M?!@L:b[
//获得文件长度 ^|H={pd'c0
public long getFileSize() y~fKLIoz"
{ w9{C"K?u=
int nFileLength = -1; As<B8e]
try{ +x(#e'6p
URL url = new URL(siteInfoBean.getSSiteURL()); R*:>h8
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); V:$+$"|
httpConnection.setRequestProperty("User-Agent","NetFox"); RN[I%^$"
SRwD`FF
|~r-VV(=
int responseCode=httpConnection.getResponseCode(); T5 (|{-
if(responseCode>=400) tLBtE!J$[
{ #obRr#8
processErrorCode(responseCode); z%OKv[/N
return -2; //-2 represent access is error @^xtxtjzux
} 4);_f
!bP%\)5
"!~o
String sHeader; ,;_+o]
)P$|9<_q7x
T1]?E]m{
for(int i=1;;i++) 7Ml4u%?
{ h:nybLw?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ikW[lefTq
//Utility.log(in.readLine()); t N{S;)q#X
sHeader=httpConnection.getHeaderFieldKey(i); `&M,B=E
if(sHeader!=null) sU"%,Q5
{ vd{QFJ
if(sHeader.equals("Content-Length")) 9<6q(]U
{ ovdJ[bO
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); >> zd
break; Y3Fj3NwS
} O2?C *
} 1@DC#2hPr
else 9@lWI
break; ZEAUoC1E1
} JVYH b 60Z
} v1TFzcHl<
catch(IOException e){e.printStackTrace ();} Ho>Np&
catch(Exception e){e.printStackTrace ();} xWxc1tT`
93>4n\
Qc; kj
Utility.log(nFileLength); D5TDg\E
gcU*rml
r3W3;L
return nFileLength; 4f([EV[6dK
} lH}KFFbp
c-sjYJXKM*
Q?#I{l)V(
//保存下载信息（文件指针位置） 2;8m0+tl
private void write_nPos() `gX@b^
{ 1^!SuAA@
try{ c+ oi8G
output = new DataOutputStream(new FileOutputStream(tmpFile)); TmsIyDcD~
output.writeInt(nStartPos.length); ~SnUnNDm`
for(int i=0;i<nStartPos.length;i++) j*jUcD*
{ *.DC(2:o!
// output.writeLong(nPos); ilA45@
output.writeLong(fileSplitterFetch.nStartPos); 0NXH449I=
output.writeLong(fileSplitterFetch.nEndPos); mQj=-\p
} }yz>(Pq
output.close(); V ~C$|+>e
} *\sPHz.
catch(IOException e){e.printStackTrace ();} ;2p+i/sVj
catch(Exception e){e.printStackTrace ();} D|N4X`T`
} .Q{RTp
Bqq=2lj
an"&'D}U
//读取保存的下载信息（文件指针位置） *MP.YI:h
private void read_nPos() 2 T!Tiu
{ ^"WVE["
try{ M|WBJ'#x0
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Y%pab/Y
int nCount = input.readInt(); -8Jw_
nStartPos = new long[nCount]; CM;b_E)9)f
nEndPos = new long[nCount]; o~Se[p
for(int i=0;i<nStartPos.length;i++) 6l#x1o;
{ ,NSf
nStartPos = input.readLong(); .Pb-{!$Ni
nEndPos = input.readLong(); U1[)eD`
} M:S-%aQ_<y
input.close(); 3Q=^&o0fl
} Gv:~P_vBH[
catch(IOException e){e.printStackTrace ();} t|aV:x
catch(Exception e){e.printStackTrace ();} #BC"bY
} 'nmA!s
&*C5Nnlv
"Ms;sdjg}&
private void processErrorCode(int nErrorCode) W>K^55'
{ E}@C4pS
System.err.println("Error Code : " + nErrorCode); " kDiK`i
} J2YQdCL
jD: N)((
]A*}Dem*5
//停止文件下载 Q7BbST+
public void siteStop() rE3dHJN;
{ {& o^p!
bStop = true; t" .Ytz>
for(int i=0;i<nStartPos.length;i++) BVQy@:K/
fileSplitterFetch.splitterStop(); p/.8})c1r
p4`1^}f&Ie
G]^[i6PQs
} : T*Q2
} BOs/:ZbK0W
//负责部分文件的抓取 Shm> r@C?
**FileSplitterFetch.java /^.|m3
*/ (WM3(US|
package NetFox; aurs~
2u"lc'9v
"y1Iu
import java.io.*; YR%iZ"`*+O
import java.net.*; NAbVH{*\U
dbI>\khI
oQ!M+sRmF
public class FileSplitterFetch extends Thread { :E:e ^$p
T$4{fhV \
zWHq4@K
String sURL; //File URL $l7^-SK`E
long nStartPos; //File Snippet Start Position k3~9;Z
long nEndPos; //File Snippet End Position 0> f!S` *
int nThreadID; //Thread's ID E5k)~P`|
boolean bDownOver = false; //Downing is over nM,:f)z
boolean bStop = false; //Stop identical | f#wbw
FileAccessI fileAccessI = null; //File Access interface 8nz({Mb9Z
U{U"%XdO
Q;M\fBQO}&
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ?,} u6tH
{ $3-vW{<
this.sURL = sURL; ys[Li.s:
this.nStartPos = nStart; }F`|_8L*v)
this.nEndPos = nEnd; oMh$:jR$
nThreadID = id; odRiCiMH
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6Rc=!_v^
} !jCgTo y
i?00!t
v+c>iI
public void run() d2k-MZuT6
{ %uW=kr
while(nStartPos < nEndPos && !bStop) gP^2GnjHL8
{ hHs/Qtq
#6`5-5Ks;
Ndmt$(b
try{ Fn4v/)*H
URL url = new URL(sURL); 2*#|t: (c
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); f5jl$H.
httpConnection.setRequestProperty("User-Agent","NetFox"); JF~i.+{h
String sProperty = "bytes="+nStartPos+"-"; =L6#=7hcl
httpConnection.setRequestProperty("RANGE",sProperty); Gp"GTPT{
Utility.log(sProperty); ?J}Q&p.
c_lHj#A(l
)>volP
InputStream input = httpConnection.getInputStream(); {SoI;o_>
//logResponseHead(httpConnection); v4$/LUJZp
5]xuU.w'
#c"eff
byte[] b = new byte[1024]; lCi{v.
int nRead; mU'<:gL+
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) RNg?o[S
{ lu8G$EQI
nStartPos += fileAccessI.write(b,0,nRead); ys_2?uv
//if(nThreadID == 1) _)A|JC!jId
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8tY>%A~^z
} U&?hG>
SI(f&T(
|,8z"g
Utility.log("Thread " + nThreadID + " is over!"); -<iP$,bq72
bDownOver = true; @[GV0*yz$
//nPos = fileAccessI.write (b,0,nRead); 6j#JhcS+
} d2\!tJm
catch(Exception e){e.printStackTrace ();} >{#JIG.
} %#6@PQ[R.
} wxN)dB
qJey&_
}@DCcf$<
//打印回应的头信息 )SV.|
public void logResponseHead(HttpURLConnection con) j=\h|^gA
{ WI8}_){ d
for(int i=1;;i++) 9zaNfs
{ [Nyt0l "z
String header=con.getHeaderFieldKey(i); $d?+\r:I{,
if(header!=null) 6].[z+
//responseHeaders.put(header,httpConnection.getHeaderField(header)); MP]<m7669*
Utility.log(header+" : "+con.getHeaderField(header)); Na\ZV|;*tu
else j3-YZKpg
break; `Sod]bO +U
} 4u{S?Ryy
} Y&|Z*s+ +}
m5Bf<E,c
bR\7j+*&
public void splitterStop() XS<>0YM
{ $vn6%M[
bStop = true; sdp&D@
} 2e48L677-
d;i|s[6ds`
K<JzIuf&
} ts]e M1;
FU`(mQ*Yd
|/.J{=E0K
/* 5Qgu:)}
**FileAccess.java 2"/MM2s
*//文件访问(定位，写) l#)X/(?;
package NetFox; {UiSa'TR1b
import java.io.*; `oRyw6Sko
3?OQ-7,
n#_B4UqW%
public class FileAccessI implements Serializable{ u{1R=ML
Ky3mzw|
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9QZaa(vN
RandomAccessFile oSavedFile; lu utyK!
long nPos; qF)J#$4;6
u?').c4
awLvLkQb{
public FileAccessI() throws IOException pEyZH!W
{ I&PJ[U#~a
this("",0); )f8>kz(
} u@a){A(P
y\Wn:RR1[
2+]5}'M
public FileAccessI(String sName,long nPos) throws IOException ,EqQU|
{ *v<f#hB"
oSavedFile = new RandomAccessFile(sName,"rw"); kk4 |4
this.nPos = nPos; !$I~3_c
oSavedFile.seek(nPos); sz7*x{E
} kc'$4 J4Tw
%VHy?!/
DP_b9o \5
public synchronized int write(byte[] b,int nStart,int nLen) Iix,}kzss
{ r&=ulg
int n = -1; ,BdObx
try{ ct+F\:e
oSavedFile.write(b,nStart,nLen); $QbJT`,mr
n = nLen; W'G|sk
} d_[H|H9i6
catch(IOException e) 1(' wg!
{ %-hSa~20
e.printStackTrace (); uWS]l[Ga
} )Q2Ap&
[@$ SLl^Y
]:%DDlRb
return n; ?G{0{c2
} q~`hn(S
2mY!gVi
<^S\&v1C_
} s.1F=u9a
y6 (L=$+B
4[ uqsJB
/* >`QBN1 Y
**SiteInfoBean.java oXo>pl
*/ 5SFr E`
package NetFox; }G4I9Py
"&L8d(ZuA
,%!m%+K9a
public class SiteInfoBean { ?;~!C2Zs
N2:Hdu:
` w;Wud'*<
private String sSiteURL; //Site's URL 14$%v;Su4
private String sFilePath; //Saved File's Path xd?=#d
private String sFileName; //Saved File's Name NKY|Z\
private int nSplitter; //Count of Splited Downloading File n6Oz[7M
B>{%$@4
(l5p_x
public SiteInfoBean() Q0A4}
{//nSplitter的缺省值为5 SQMl5d1d:
//default value of nSplitter is 5 (Cr
this("","","",5); bPsvoG
} zAB= >v
eP~bl
4Kqo>|C
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) ]($ \7+
{ YS3~sA
sSiteURL= sURL; WZa6*pF
sFilePath = sPath; -TD\?Q
sFileName = sName; }L0 [Jo:
this.nSplitter = nSpiltter; s|IBX0^@
OvH:3"Sdy
EBhdP
} |v+z*}fKw
9J:|"@)N
l|q-kRRjn
public String getSSiteURL() d` GN!^
{ %/dOV[/
return sSiteURL; t 7Y*/v&P(
} @9^OHRZX
F:/x7]7??Z
?NBae\6r
public void setSSiteURL(String value) !7t&d
{ %oBP6|e
sSiteURL = value; zw#n85=
} =r]l"T
Xg~9<BGsi
stiF`l
public String getSFilePath() 81nD:]7
{ )\])?q61
return sFilePath; j_C"O,WS
} (wj:Gc
?}`-?JB1
c0wLc,)G
public void setSFilePath(String value) !'_7MM
{ ~\=D@G,9
sFilePath = value; 7U7!'xU
} 8#!g;`~ D
~vTwuc\(H
eEXNEgbn
public String getSFileName() cB&_':F
{ -9vNV:c
return sFileName; U\%r33L )
} RUY7Y?
kq| !{_
G#[A'tbKk
public void setSFileName(String value) *iB&tWv
{ eb7UA=[Z
sFileName = value; 3cHYe
} A=kOSq 4Q
Cab-:2L]
1$RJzHS
public int getNSplitter() 4?Y7.:x
{ aEdA'>
return nSplitter; f2~Aug
} <T>s;b
MK3h~`is
nlpEkq
public void setNSplitter(int nCount) VL)<u"d4
{ H!*ypJ
nSplitter = nCount; #E+ybwA
} \MEBQ
} et5lfj
l%}q&_
bci]"uzB
/* <M\&zHv
**Utility.java he(K
*/ x8aOXN#w}
package NetFox; LZ wCe$1
yF\yxdUX#
wa<k%_# M
public class Utility { 3qTr|8`s
t U}6^yc
)W=O~g
public Utility() Q u2 ~wp<
{ uZ8-?
Xz@#,F:@
k.C&6*l!5;
} }E ]l4N2
#b/L~Bw[
//线程睡眠 U[MeK)*
public static void sleep(int nSecond) xO_>%F^?
{ HW]?%9a
try{ q\@_L.tc[
Thread.sleep(nSecond); =4`wYh
} umns*U%T;
catch(Exception e) T1q27I
{ i&m_G5u88
e.printStackTrace (); 2.WI".&y=
} %16Lo<DPm
} R*vQvO%)h
,c"J[$i$
//日志 VwH|ed$
public static void log(String sMsg) {C&Uq#V
{ 1UK= t
System.err.println(sMsg); "dP-e
} ,c:NdY(,)
tC|?Kl7
i.'"`pn_
public static void log(int sMsg) U',C-56z
{ msxt'-$M
System.err.println(sMsg); d4ecF%R
} w:lj4Z_
} A:Wr5`FJ
1J0gjO)AZ
/?r A|
/* <Q(E {c3"
**TestMethod.java ntLEk fK{
*/ 8\68NG6o
package NetFox; H?O5 "4a
_{c_z*rM8
?fH1?Z\'K
public class TestMethod { cO7ii~&%!
O)`L( x
:+6W%B
public TestMethod() q83^?0WD
{ ///xx/weblogic60b2_win.exe FkrXM!mJ
try{ h,FU5iK|
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +rU{-`dy9'
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); IDn<5#
SiteFileFetch fileFetch = new SiteFileFetch(bean); ;4!H- qZ
fileFetch.start(); MlYm\x8{M
} (1|wM+)"
catch(Exception e){e.printStackTrace ();} `bBkPH}M
\}4Y]xjV2
YIwa =^
} /i8OyRpSyk
CIMI?
~588M 8~
public static void main(String[] args) P!Fykg
{ }xC2~
new TestMethod(); Pw<'rN8''
} C]2-V1,ZX
} AuK$KGCI=
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