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)); _=cMa's
} 'Y-c*q
for(int i=0;i<nEndPos.length-1;i++) M2m@N-+R
{ \C>I6{
nEndPos = nStartPos[i+1]; )X7ZX#ttH
} 5ax/jd~}
nEndPos[nEndPos.length-1] = nFileLength; .vb*|So
} $QY(7Z"
} &KD m5p
OgzPX^q/=
.+8w\>w6g
//启动子线程 gFW1Nm_DJ
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; {j(,Q qB;f
for(int i=0;i<nStartPos.length;i++) k!!o!rBS
{ `5gcc7b
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), y6Rg@L&U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), sF}E=lY
nStartPos,nEndPos,i); a{{([uZ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ho0T$hB
fileSplitterFetch.start(); !e%#Zb MIo
} Kj}}O2
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), le1'r>E$
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); /*8"S mte
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", he!e~5<@y
nEndPos = " + nFileLength); Ok,hm.|
// fileSplitterFetch[nPos.length-1].start(); 6 .*=1P*?
udw5A*Ls
PvO>}(=
//等待子线程结束 j:fL_1m
//int count = 0; bhFzu[B
//是否结束while循环 -\r*D#aHBN
boolean breakWhile = false; qf'uXH
O1-Ne.$
l3.HL> o
while(!bStop) 4s3n|6v
{ 7gvkd+-*
write_nPos(); #LcF;1o%o2
Utility.sleep(500); \N!k)6\
breakWhile = true; =0O`VSb
6Siz9
]ul]L R%.
for(int i=0;i<nStartPos.length;i++) !d^5mati)T
{ `L0}^|`9
if(!fileSplitterFetch.bDownOver) QQ pe.oF
{ S3.Pqp_<
breakWhile = false; rrmr#a
break; w+[r$+z!k
} T?Hs_u{
} [NyR$yD{
if(breakWhile) l'mgjv~
break; e6,/i
mKn:EqA
8 \%*4L'
//count++; m+,a=sR
//if(count>4) f%d7?<rw
// siteStop(); 3~"G27,
} +Z/Pj_.o
D/Bb)]9I
LzP+l>m
System.err.println("文件下载结束！"); l2._Z Py
} B`9'COw
catch(Exception e){e.printStackTrace ();} O cd ^{u
} 4IIe1 .{
O~trv,?)
6[w_/X"
//获得文件长度 6-j><'
public long getFileSize() K+2<{qwh
{ x^xlH!Sc
int nFileLength = -1; 0LeR#l:I
try{ auK*\Wjm?
URL url = new URL(siteInfoBean.getSSiteURL()); w+z~Mz}Vz
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); _e7Y R+
httpConnection.setRequestProperty("User-Agent","NetFox"); `[X5mEe
w<*6pPy
<$qe2FtUq
int responseCode=httpConnection.getResponseCode(); y)CnH4{
if(responseCode>=400) NirG99kyo
{ sWa`-gc
processErrorCode(responseCode); ZvM~]8m
return -2; //-2 represent access is error XE6sFU
} aHuZzYQ*"j
ER;?[!
g\ilK:r}
String sHeader; Hyh$-iCa
)7f;FWI
3"!h+dXw
for(int i=1;;i++) `O/1aW1
{ )O;6S$z9Y
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); YHSdaocp
//Utility.log(in.readLine()); =ss(~[
sHeader=httpConnection.getHeaderFieldKey(i); KP,#x$Bg
if(sHeader!=null) J2W#vFe\
{ bvzNur_
if(sHeader.equals("Content-Length")) THEpW{.E
{ %{Ib
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); }M7{~ov#s
break; (#KSwWo{ed
} O*jTrZ(k
} UNY O P{
else wIeF(}VM
break; 8~* |muN.e
} ,6@s N'c
} >h)D~U(H
catch(IOException e){e.printStackTrace ();} eO%w i.Q
catch(Exception e){e.printStackTrace ();} *62Cf[a
6Uh_&?\%
[L(qrAQ2|z
Utility.log(nFileLength); [A\DuJx
)IBvm1
BLaF++Fop
return nFileLength; 8/gA]I 6=#
} }ZqnsLu[)
l/xpAx
@qUgp*+{
//保存下载信息（文件指针位置） T"IDCT'z
private void write_nPos() )>"|<h.2]
{ {3Y R_^>?
try{ 7!sR%h5p
output = new DataOutputStream(new FileOutputStream(tmpFile)); emT/5'y
output.writeInt(nStartPos.length); #|j8vmfn$e
for(int i=0;i<nStartPos.length;i++) W79Sz}):
{ 2^w8J w9
// output.writeLong(nPos); WQiIS0BJ *
output.writeLong(fileSplitterFetch.nStartPos); 3QhQpPk),
output.writeLong(fileSplitterFetch.nEndPos); p!/!ZIo
} .~O- <P#
output.close(); u(W>HVEG
} |1%eo.
catch(IOException e){e.printStackTrace ();} .+) AeGh
catch(Exception e){e.printStackTrace ();} ^#gJf*'UE
} =|LB,REN
J.(mg D
)ko[_OJj
//读取保存的下载信息（文件指针位置） XOL_vS24
private void read_nPos() kxCN0e#_
{ `T,^os#6
try{ ]bP1gV(b-
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); oM^VtH=>
int nCount = input.readInt(); Ua.%?V
nStartPos = new long[nCount]; j4wsDtmAU
nEndPos = new long[nCount]; U<|*V5
for(int i=0;i<nStartPos.length;i++) sK@]|9ciQ
{ $Sgq7
nStartPos = input.readLong(); 3~%M4(
nEndPos = input.readLong(); MK.TBv
} 7Y.mp9,
input.close(); yZ-Ql11
} Y41b8.|P+
catch(IOException e){e.printStackTrace ();} :#OaE,
catch(Exception e){e.printStackTrace ();} T@xaa\bzg
} #AH gY.
Ca["tks
o'_eLp
private void processErrorCode(int nErrorCode) c?*x2Vk
{ *P\OP'o_
System.err.println("Error Code : " + nErrorCode); }XD=N#p@z
} *7{{z%5Pu
W0S\g#
4N)45@jk[
//停止文件下载 zmg :Z p=
public void siteStop() 06 an(&a9
{ +^q-v-
bStop = true; 7O~hA*Z
for(int i=0;i<nStartPos.length;i++) ZEB,Q~
fileSplitterFetch.splitterStop(); by$S#ef
Lh-+i
ikb;,Js
} PKZMuEEy,
} IN@ =UAc&
//负责部分文件的抓取 3F9dr@I.7
**FileSplitterFetch.java K_Kz8qV.?
*/ 4|hfzCjMI
package NetFox; })?KpYk
|[@v+koq
),@m 3wQ
import java.io.*; &r!jjT
import java.net.*; C_ W%]8u
8#|PJc
t; @T~%
public class FileSplitterFetch extends Thread { ${tBu#$-d
{tuGkRY2~
acI%fYw5p`
String sURL; //File URL _o-01gu.
long nStartPos; //File Snippet Start Position h`D+NZtWm
long nEndPos; //File Snippet End Position t?FPmbjv
int nThreadID; //Thread's ID yG<Q t+D
boolean bDownOver = false; //Downing is over iwfH~
boolean bStop = false; //Stop identical ~,{nBp9*
FileAccessI fileAccessI = null; //File Access interface qJK6S4O]
|iVw7M:
m,SWG[~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i+|/V&#3[
{ mW#p&{
this.sURL = sURL; uXdR-@80*
this.nStartPos = nStart; Lmc"qFzK
this.nEndPos = nEnd; -V52?Hq
nThreadID = id; #Qd"d3QG
fileAccessI = new FileAccessI(sName,nStartPos);//定位 WE&"W$0
} {+ WI>3
9U!#Y%*T
41o~5:&
public void run() ~GjM:*
{ H?j}!JzAC
while(nStartPos < nEndPos && !bStop) E>rWm_G
{ *%QTv3{
T0BM:ofx
SI;SnF'[7
try{ (L"G,l
URL url = new URL(sURL); k^\>=JTq=
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ]dHV^!
httpConnection.setRequestProperty("User-Agent","NetFox"); ea!Znld]
String sProperty = "bytes="+nStartPos+"-"; R1\$}ep^
httpConnection.setRequestProperty("RANGE",sProperty); 0^3@>>^
Utility.log(sProperty); K[i|OZWu
R^GLATM
u )KtvC!
InputStream input = httpConnection.getInputStream(); %I;iP|/
//logResponseHead(httpConnection); 'q{|p+
G8F43!<
9h'klaE(
byte[] b = new byte[1024]; Z#|IMmT;*=
int nRead; qjd8Q
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) q/t~`pH3
{ G1:2MPH
nStartPos += fileAccessI.write(b,0,nRead); T\o!^|8
//if(nThreadID == 1) ahm@ +/2
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9h 0^_|"
} vq*)2.
hh"=|c
,a?$F1Z-
Utility.log("Thread " + nThreadID + " is over!"); dtUt2r)6L;
bDownOver = true; OcGHMGdn
//nPos = fileAccessI.write (b,0,nRead); )qx,>PL
} [lX3":)
catch(Exception e){e.printStackTrace ();} -4'yC_8t
} cakb.Q
} ~85Pgb<
7nL3+Pq
jaImO
//打印回应的头信息 tL~?)2uEN
public void logResponseHead(HttpURLConnection con) @}@J$ g
{ #35@YMF
for(int i=1;;i++) Um9]X@z
{ ?$LKn2C
String header=con.getHeaderFieldKey(i); b_T?jCyW
if(header!=null) +yd(t}H@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); h_:|H8t;w
Utility.log(header+" : "+con.getHeaderField(header)); pg'3j3JW$
else ?H_'L4Wv
break; B!cg)Y?.bd
} Y l1sAf/
} pu +"bq
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9@."Y>1G
public void splitterStop() , 1{)B
{ -5 YvtL
bStop = true; idr,s\$>
} *n=NBkq%/!
UR&Uwa&.
l[q%1-N
} a}+7MEUmZ/
tj_+0J$sw:
d8? }69:h
/* V_g9oR_
**FileAccess.java YkKq}DXj
*//文件访问(定位，写) '<C I^5^
package NetFox; wcT0XXh
import java.io.*; tGs=08`
t$z FsFTQ
uwl;(zwh_
public class FileAccessI implements Serializable{ U'st\Dt
]&3UF?
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4 }l,F
RandomAccessFile oSavedFile; =yfLqU
long nPos; K>TdN+Z}=
`V@{#+X
"mnWqRpX
public FileAccessI() throws IOException rlvo&(a
{ hN6j5.x%
this("",0); tVZjtGz=
} h,q%MZ==^s
Elt=/,v`!
JU7EC~7|2c
public FileAccessI(String sName,long nPos) throws IOException {ZH9W
{ i!jZZj-{
oSavedFile = new RandomAccessFile(sName,"rw"); Ch`XwLY9
this.nPos = nPos; Z~tOR{q
oSavedFile.seek(nPos); Yw=Ve 0
} w<*tbq
1pC!F ;9Oo
n^|n6(EZ
public synchronized int write(byte[] b,int nStart,int nLen) adh=Kp e!w
{ s% "MaDz
int n = -1; :luVsQ
try{ 8kw`=wSH>
oSavedFile.write(b,nStart,nLen); bE2^sx`(
n = nLen; DD\:glo
} "z\T$/
catch(IOException e) @X_x?N
{ EZz Ox(g
e.printStackTrace (); udDhJ?
} k+2~=#
lvIKL!;H
"w0>
return n; sn&y;Vc[$
} P=eVp(/x
F_=RY]
4G&E?
} ja}_u}:
l;: L0(('
Z9s tB>?
/* U7.3`qd"
**SiteInfoBean.java <Brq7:n|
*/ 5YaTE<G
package NetFox; PD12gUU?
BEyg63=
U[=VW0
public class SiteInfoBean { z%;b-PpS
- *!R
}<o.VY&;.
private String sSiteURL; //Site's URL m(E-?VMHo
private String sFilePath; //Saved File's Path s_-G`xT>{
private String sFileName; //Saved File's Name 1+RG@Cp
private int nSplitter; //Count of Splited Downloading File D(D:/L8T,
5BCXI8Ox9x
[f}YXQ0N)
public SiteInfoBean() *{8Kb>D
{//nSplitter的缺省值为5 "qUUH4mR`
//default value of nSplitter is 5 ('pNAn!]
this("","","",5); eKNZ?!c=
} ~;k-/Z"
^AK<]r<?L?
H#x=eDU|k
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) HDZB)'I
{ oCdWf63D
sSiteURL= sURL; "5u*C#T2$
sFilePath = sPath; 5G cdz
sFileName = sName; -?`^^v
this.nSplitter = nSpiltter; "Q6oPDX(
+uKh]RP
$^?"/;8P5
} S\K;h/;V
lN#W
0P^RciC f
public String getSSiteURL() 0Lmq?D
{ Esvr~)Y
return sSiteURL; %719h>$
} TJ8IYo| D
.'JO7of
Y%y=
public void setSSiteURL(String value) j'FSd*5m
{ a]-F,MJ
sSiteURL = value; ec+&K?T
} %!I7tR#;
?U.+SQ
awh<CmcZ
public String getSFilePath() E|Mu1I]e
{ {J;[ Hf5
return sFilePath; 3:Q5dr+1_
} ^.)oQo SE
rpH ,c[D
$q,2VH:Ip
public void setSFilePath(String value) (CFm6p'RZ
{ *Z\B9mx
sFilePath = value; 2\80S[f
} P}hHx<L
AL@8v=
o0nd]"q?
public String getSFileName() dPZrX{ c
{ S?ELFq(g
return sFileName; !m8MyZ}%
} 4FUY1p
y(/"DUx
EYWRTh
public void setSFileName(String value) @=JOAo
{ KBJ%$OQV
sFileName = value; `&y Qtj# '
} 2GeJ\1k
>tc#Ofgzd
|j:"n3~6
public int getNSplitter() B!{vSBq
{ nk=+6r6
return nSplitter; FyleK+D?
} !YX$4_I
lz1RAp0R"
}#%3y&7M7
public void setNSplitter(int nCount) I!sh+e
{ @GTkS!86
nSplitter = nCount; G*;?&;*
} t<=Ru*p
} 4z6i{n-k
N8*6sK.
b,C2(?hg
/* 0Va+l)F
**Utility.java AzFd#P
*/ 3XykIj1
package NetFox; aE aU_f/
3an9Rb V
1,Ams
public class Utility { .+ezcG4q
jGm`Qg{<
4)Jtc2z7Z\
public Utility() )ZZjuFQJ)
{ oVZI([O
8M6 Xd]{%
GK6/S_l%D+
} stxei 6
3{:AG,G
//线程睡眠 /H (55^EMZ
public static void sleep(int nSecond) ;*{"|l qe
{ ujin+;1
try{ 1s-dqHz"s
Thread.sleep(nSecond); 8NF93tqD6
} lL\%eQ
catch(Exception e) 1>yh`Bp\=
{ I8x,8}o>V
e.printStackTrace (); lIhP\:;S&
} Aj{c s
} Yamu"#
#}xw *)3
//日志 7y?aw`Sw:
public static void log(String sMsg) ^5'pJ/BV
{ CE5A^,EsB
System.err.println(sMsg); ']bw37_U,
} #zf,%IYF
: Iq
qkbGM-H%U
public static void log(int sMsg) 8NZQTRdH
{ #}p@+rkg2
System.err.println(sMsg); Y+d+
} C^IPddw>
} fEo5j`}
u~xfI[8C
\; voBU
/* &wa2MNCG8
**TestMethod.java \<aR^Sj.
*/ ]5O]=^ u0
package NetFox; ~dBx<
+$YHdgZ.
41v#|%\w
public class TestMethod { Q2>o+G
Z35(f0b
#b eLo J
public TestMethod() J))U YJO
{ ///xx/weblogic60b2_win.exe 'NNfzh
try{ *Y':raP
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); +;ylld
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ym8pB7E7%
SiteFileFetch fileFetch = new SiteFileFetch(bean); G,}"}v:
fileFetch.start(); 7'!DK;=TD6
} *{("T
catch(Exception e){e.printStackTrace ();} +>ld
h e[2,
sOO_J!bblP
} 8AJ#].q0F
S}P rgw/
$x*(D|\'<
public static void main(String[] args) W6s-epsRmT
{ LP'wL6#
new TestMethod(); mpNS}n6
} mndKUI}d
} 6~-,.{Y
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