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)); u&4CXv=
} 5ggmS<=
for(int i=0;i<nEndPos.length-1;i++) fZQL!j4
{ q/T(s
nEndPos = nStartPos[i+1]; t "y[
} -NzO,?
nEndPos[nEndPos.length-1] = nFileLength; DlC\sm
} Zl,c+/
} }"} z7Xb0
So?.V4aD_
'u9,L FO
//启动子线程 8H2zMIB
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 3k YVk
for(int i=0;i<nStartPos.length;i++) N$'/J-^
{ 2!-?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), oJ\)-qSf
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), (CUrFZT$
nStartPos,nEndPos,i); 1Yr&E_5/
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); N5W;Zx]
fileSplitterFetch.start(); b5!\"v4c
} NO$n-<ag
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), |E{tS,{OhJ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); ]JGh[B1gh
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", FEOr'H<3x
nEndPos = " + nFileLength); L >* F8|g
// fileSplitterFetch[nPos.length-1].start(); +SM&_b
M't~/&D#
|X}H&wBWo
//等待子线程结束 j[E8C$lW
//int count = 0; '(ZJsw
//是否结束while循环 ]V*ku%L0
boolean breakWhile = false; 6snDv4
0^%\! Xxq
3K{XT),
while(!bStop) A%Ov.~&\G
{ =J@M,mbHg
write_nPos(); bIvF5d>9#K
Utility.sleep(500); [_$r-FA
breakWhile = true; :eK(9o
l ~bjNhk
)7X+T'?%
for(int i=0;i<nStartPos.length;i++) B: '}SA{
{ 6CQ.>M:R
if(!fileSplitterFetch.bDownOver) $5(_U
{ "o| f
breakWhile = false; +&AKDVmx
break; W|~Jl7hs8Q
} #=}dv8
} =O~ J
if(breakWhile) sObH#/l`
break; M lv
KOQiX?'
Z.Otci>J
//count++; {c 82bFiv
//if(count>4) ,]:vk|a#;
// siteStop(); "7w~0?}
} .,-,@ZK
.2K4<UOAbm
a'NxsByG]s
System.err.println("文件下载结束！"); \IL;}D{
} fPW|)e"
catch(Exception e){e.printStackTrace ();} ujlIWQU2mo
} $`KddW0_
Mx-? &
,H_b@$]n8
//获得文件长度 7m4gGkX#r
public long getFileSize() 4yZ'+\ +I
{ s!lLdR[g
int nFileLength = -1; %NyV2W=~X
try{ 3CKd[=-Z
URL url = new URL(siteInfoBean.getSSiteURL()); rLkUIG
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 9EPE.+ns
httpConnection.setRequestProperty("User-Agent","NetFox"); v jTs[eq>
YsX&]4vzm
>DFpL$oP
int responseCode=httpConnection.getResponseCode(); n;Nr[hI
if(responseCode>=400) *qX!
{ p"xti+2,
processErrorCode(responseCode); >e g8zN
return -2; //-2 represent access is error t)#dR._q
} 9/8#e+L
+*I'!)T^B
S":55YQev!
String sHeader; #!A'6SgbkM
qw#wZ'<n
<yoCW?#
for(int i=1;;i++) FW~{io]n
{ .Mn_T*F
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); U<pGP
//Utility.log(in.readLine()); pCB^\M%*
sHeader=httpConnection.getHeaderFieldKey(i); tK $r_*
if(sHeader!=null) N5ph70#y3
{ 3SI~?&HU!/
if(sHeader.equals("Content-Length")) +hUS sR&
{ .5S< G)Ja
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); KA[8NPhzZ
break; I.4o9Z[?
} P#0U[`ltK
} Moldv x=M
else A`5/u"]*D
break; WfdM~k\
} "e3T;M+
} i 4}4U
catch(IOException e){e.printStackTrace ();} WxLmzSz{xD
catch(Exception e){e.printStackTrace ();} RJYB=y8l
P"Scs$NOU?
zeC@!,lH
Utility.log(nFileLength); Z(|@C(IL0\
mQbpv'N
Mk3~%`
return nFileLength; uVSc1MS1
} 0h3-;%
tRUGgf`
?(t{VdZSzQ
//保存下载信息（文件指针位置） _mEW]9Sp
private void write_nPos() he vM'"|4
{ hJ)\Vo
try{ 7EfLd+
output = new DataOutputStream(new FileOutputStream(tmpFile)); =6sA49~M
output.writeInt(nStartPos.length); +i\ +bR
for(int i=0;i<nStartPos.length;i++) lc:dKGF6
{ ~x(1g;!^
// output.writeLong(nPos); p aQ"[w
output.writeLong(fileSplitterFetch.nStartPos); b}f#[* Z
output.writeLong(fileSplitterFetch.nEndPos); j O-H1@;
} J~e%EjN5e
output.close(); T#o?@;
} o+wG69
catch(IOException e){e.printStackTrace ();} '\,|B x8Q
catch(Exception e){e.printStackTrace ();} ?k 4|;DD
} Iu)76Y@=5=
qe/|u3I<lF
i[+cNJ|$B0
//读取保存的下载信息（文件指针位置） A89n^@
private void read_nPos() ]* #k|>Fl
{ Np.] W(
try{ @5[9iY
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Tc3~~X
int nCount = input.readInt(); nEG+TRZ)\
nStartPos = new long[nCount]; 0\y{/P?I$
nEndPos = new long[nCount]; fQ[& ^S$
for(int i=0;i<nStartPos.length;i++) UI?AM 34
{ @)\{u$
nStartPos = input.readLong(); 1xBg^
nEndPos = input.readLong(); Q.b<YRZ
} x;w^&<hQ\
input.close(); G*`H2-,
} ,Ky-3p>
catch(IOException e){e.printStackTrace ();} bV3az/U
catch(Exception e){e.printStackTrace ();} I7S#vIMXR.
} .5tE, (<?
Uo~-^w}
!5wuBJ0
private void processErrorCode(int nErrorCode) mY'c<>6t
{ aFbIJm=!
System.err.println("Error Code : " + nErrorCode); 3IlflXb
} rw|;?a0
h1A/:/_M6
pBbfU2p
//停止文件下载 >RTmfV
public void siteStop() 7GFE5>H
{ DHnO ,"
bStop = true; ^&Exa6=*FT
for(int i=0;i<nStartPos.length;i++) 6-+q3#e
fileSplitterFetch.splitterStop(); YVcO+~my
C4].egVg
"44A#0)B'l
} NI%&Xhn!*>
} Cj +{%^#
//负责部分文件的抓取 M'gL_Xsei
**FileSplitterFetch.java T, z80m}
*/ nZtP!^#
package NetFox; fqY;>Z
^^;#Si
9_4bw9A
import java.io.*; nYvx[ zq?^
import java.net.*; 8M~^/Zc
y$Y*%D^w
ov9+6'zya
public class FileSplitterFetch extends Thread { VJf|r#2
Uc[@]
?x\tE]
String sURL; //File URL $oo`]R_
long nStartPos; //File Snippet Start Position K8R}2K-Y
long nEndPos; //File Snippet End Position m4r!Ck|
int nThreadID; //Thread's ID qb[UA5S\`
boolean bDownOver = false; //Downing is over :g+5cs
boolean bStop = false; //Stop identical sN_c4"\q
FileAccessI fileAccessI = null; //File Access interface bzC|aUGM
'LyEdlC]
tx9;8K3
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException p_g#iH!*
{ 7C::%OF~7
this.sURL = sURL; G%q^8#
this.nStartPos = nStart; BPwn!ii|
this.nEndPos = nEnd; wJr5[p*M
nThreadID = id; H?a1XEY/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 kLfk2A;'i
} Y+kfMAv
m) -DrbE
JHvawFBN<u
public void run() A#@9|3
{ !,0%ZG}]7
while(nStartPos < nEndPos && !bStop) q\r@x-&g+
{ qx;8Hq(E[
|u@/,x/t
zQ=c6xvm8
try{ gd,3}@@SH
URL url = new URL(sURL); T!F0_<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 5dNM:1VoE
httpConnection.setRequestProperty("User-Agent","NetFox"); d8p<f+
String sProperty = "bytes="+nStartPos+"-"; M#CYDEB
httpConnection.setRequestProperty("RANGE",sProperty); 7%0V?+]P
Utility.log(sProperty); |l#<vw wE
~M!9E])
Y;uQq-CP
InputStream input = httpConnection.getInputStream(); N6%wHNYZ
//logResponseHead(httpConnection); ^F?}MY>
.m^L,;+2
e%wzcn
byte[] b = new byte[1024]; {pR4+g
int nRead; ~ 7^#.
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) pFW^
{ !!we4tWq
nStartPos += fileAccessI.write(b,0,nRead); -H+<81"B#
//if(nThreadID == 1) dW4FMm>|
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); p "Cxe
} R?E< }\!
Xk]:]pl4W
/]@1IC{Lk
Utility.log("Thread " + nThreadID + " is over!"); a:V2(nY
bDownOver = true; 2Vwv#NAV k
//nPos = fileAccessI.write (b,0,nRead); *)|EWT?,
} 7/>#yR
catch(Exception e){e.printStackTrace ();} GX\6J]x=^2
} 8rEUZk
} Mcfqo0T-
!C3ozZ<
W-8U~*/
//打印回应的头信息 0hB9D{`,{
public void logResponseHead(HttpURLConnection con) +WTO_J7
{ qH9bo-6
for(int i=1;;i++) M. o}?
{ # ^q87y
String header=con.getHeaderFieldKey(i); ,g~Iup
if(header!=null) Kwmtt
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 6VQe?oh
Utility.log(header+" : "+con.getHeaderField(header)); z:p;Wm
else 'lIj89h<E
break; U1y8Y/
} T4fVZd)x
} v\}s(X(J
>oHgs
Q?xCb
public void splitterStop() q,%lG$0v
{ g-8D1.U
bStop = true; $uj3W<iw3E
} >&Ios<67g
\nbGdka
"+sl(A3`U
} A(84cmq!q
`ttqgv\
{Yc#XP
/* y8e'weK
**FileAccess.java s)BB(vQ]6
*//文件访问(定位，写) sn.0`Stt
package NetFox; lq_(au.
import java.io.*; (M;jnQ0
Q| _e=
A1p87o>
public class FileAccessI implements Serializable{ $9@jV<Q1
3I.0jA#T&/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 !V O^oD7
RandomAccessFile oSavedFile; 'L5ih|$>
long nPos; *I<L1g%9d
BTAt9Z8qK
3vC"Q!J&
public FileAccessI() throws IOException 4 >`2vb
{ {^V9?^?d (
this("",0); VNT*@^O_=
} vAt]N)R
'Z}3XVZEN
QJ^'Uyfdn
public FileAccessI(String sName,long nPos) throws IOException my+2@ln
{ O]cuJp
oSavedFile = new RandomAccessFile(sName,"rw"); {Q~HMe`,
this.nPos = nPos; c_ Dg0
oSavedFile.seek(nPos); bD:[r))#e
} $GJuS^@%
&$NYZ3?9
/3KPK4!m
public synchronized int write(byte[] b,int nStart,int nLen) |x+g5~$
{ jxdX7aik
int n = -1; {Lg]chJq?
try{ ;%a
oSavedFile.write(b,nStart,nLen); 8:gUo8
n = nLen; =pnMV"'9
} kdW$>Jqb
catch(IOException e) B }t529Z
{ - U Elu4n&
e.printStackTrace (); ejh0Wfl
} 0U&@;/?
EC`=nGF
#gcv])to
return n; \u$[$R5
} FnWN]9
M;j)F
]rS:#LK
} k;(r:k^
R|'ftFebB.
&\m=|S
/* ,p)Qu%'
**SiteInfoBean.java 12o6KVV^x
*/ +aZcA#%
package NetFox; T?k!%5,Kj
,JqCxb9
B6-1q& E/
public class SiteInfoBean { SSn{,H8/j
)N3XbbV
]S+KH \2
private String sSiteURL; //Site's URL Y_= ]w1
private String sFilePath; //Saved File's Path *b,4qMr
private String sFileName; //Saved File's Name h1Nd1h@-
private int nSplitter; //Count of Splited Downloading File xRbtiFk9H
*&doI%q
rr^?9M*{V
public SiteInfoBean() dGG8k&
{//nSplitter的缺省值为5 bZlKy`Z
//default value of nSplitter is 5 K:q|M?_
this("","","",5); Y|nC_7&Bv
} %Xe 74C"
{v}BtZ
Px?zih!6
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) HB*H%>L{"B
{ t_kRYdW9
sSiteURL= sURL; {wh, "Ok_
sFilePath = sPath; GQ\;f
sFileName = sName; gaWJzK Yc_
this.nSplitter = nSpiltter; i)q8p
E(!b_C&
[=]LR9c4
} ,B1~6y\b
?bGk%jjHXM
h|%a}])G)
public String getSSiteURL() zGtv(gwk
{ ht_'GBS)
return sSiteURL; ZtGtJV"H
} ]{ir^[A6
Cs'<;|r(
821;;]H
public void setSSiteURL(String value) !,9;AMO -
{ ")Qhg-l
sSiteURL = value; ;5tQV%V^Q
} (>C$8)v
N oRPvFv
fL~@v-l#~
public String getSFilePath() #CRd@k?
{ s<{) X$
return sFilePath; V/]o':
} &3f^]n!@
.&2~gA
g4^3H3Pd
public void setSFilePath(String value) +?v2MsF']
{ *nSKIDw
sFilePath = value; @tlWyUju
} B^@X1EE
Xbu P_U'
>Xi/ p$$7u
public String getSFileName() w>wzV=R
{ ?izl#?
return sFileName; p&2oe\j$,
} p:zRgwcn
#|/+znJm
}=p+X:k=
public void setSFileName(String value) >e!Y63`
{ .'bhRQY
sFileName = value; J1Run0
} @_0tq{
H;MyT Vl
`r]C%Y4?
public int getNSplitter() d' l|oeS
{ CU@}{}Yl
return nSplitter; dWP<,Z>
} R$bDj>8
SBg|V
20/P:;
public void setNSplitter(int nCount) <>H^:iqn
{ U+,RP$r@
nSplitter = nCount; *iVEO
} -tA_"q'^
} Mc{-2
z) x.6
XD Q<28^
/* dP?QPky{9
**Utility.java -z">ov-)
*/ V1yP{XT=
package NetFox; $|t={s34
hC?rHw H>
%Ix2NdC
public class Utility { p8j*m~4B
Muyi2F)j
7Q9| P?&:z
public Utility() }$b!/<7FD
{ y@rg_Paq
6+4SMf3
<c$rfjM+JU
} iKu4s
#,h0K
//线程睡眠 4UHviuOo8
public static void sleep(int nSecond) B.:1fT7lI
{ z9E*1B+
try{ <R?S
Thread.sleep(nSecond); u.Tknw-X
} s8dP=_ `
catch(Exception e) EHK+qrym
{ :LCyxLI
e.printStackTrace (); {DZ xK(
} P!I Lji!
} Q/0oe())
]QGo(+
//日志 \1hQ7:f;\
public static void log(String sMsg) g3 Oro}wt6
{ ={;7WB$
System.err.println(sMsg); mpQu:i|W
} Lngf,Of.e
kH`?^^_yJ
Pn l}<i
public static void log(int sMsg) x[xRqC vL
{ aYM~Ub:x{
System.err.println(sMsg); )iid9K<HB
} /D964VR1M\
} @9~x@[
c Qe3
`g<0FQA
/* frc9
**TestMethod.java v3{%U1>}v
*/ z[@i=avPG
package NetFox; m\70&%v
)Y6\"-M[
{yDQncq'^
public class TestMethod { 33&l.[A"!}
lOM8%{.'_x
eAStpG"*
public TestMethod() .osG"cS
{ ///xx/weblogic60b2_win.exe qWf[X'
try{ USaa#s4'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); tu(^D23
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); _l+C0lQl=
SiteFileFetch fileFetch = new SiteFileFetch(bean); tEt46]{
fileFetch.start(); O*.n;_&
} #M4LG; B
catch(Exception e){e.printStackTrace ();} 5~ZzQG
qOIVuzi*
w@Asz9Lq%
} Z}{]/=h
Xppv
Uf MQ?(,
public static void main(String[] args) qoZ)"M
{ ,.h@tN<C
new TestMethod(); EwmNgmYq
} I9m9`4BK
} e<(6x[_
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