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)); j>?nL~{
} :RukW.MR
for(int i=0;i<nEndPos.length-1;i++) lK7:qo
{ pfIK9>i
nEndPos = nStartPos[i+1]; xzOvc<u
} A'7Y{oPHX
nEndPos[nEndPos.length-1] = nFileLength; EPLHw
} {fDRVnI?
} 37:tu7e~c
QxaMe8(
Og1\6Q
//启动子线程 ?Fa$lE4
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Rf8ZH
for(int i=0;i<nStartPos.length;i++) IKnf
{ X_nbNql
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 9S17Lr*c
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), x9\{a
nStartPos,nEndPos,i); Z:,\FB_U
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FN/l/OSb
fileSplitterFetch.start(); k$m'ebrS.~
} ME]7e^
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), +PWm=;tcC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :|S[i('
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E$4H;SN \
nEndPos = " + nFileLength); Qi dI
// fileSplitterFetch[nPos.length-1].start(); w5s&Ws
bZgo}`o%
L\"wz scn
//等待子线程结束 Fje /;p
//int count = 0; '_Pb\ jK
//是否结束while循环 4clCZ@\K^
boolean breakWhile = false; W{!5}Sh
J Q*~le*
9[*P`*&
while(!bStop) 3hBYx@jTO
{ "QS(4yw?jg
write_nPos(); g8&& W_BI
Utility.sleep(500); 3AR'Zvn
breakWhile = true; Gw-{`<CxE
)BI%cD
tC$+;_=+F
for(int i=0;i<nStartPos.length;i++) j|o/>^ 'e
{ 6tP!(
if(!fileSplitterFetch.bDownOver) n} !')r
{ ow 6\j:$?
breakWhile = false; -L2 +4
break; @ YWuWF
} 2Hx*kh2
} yB*aG
if(breakWhile) /8`9SS
break; @>~S$nw/
RT'5i$q[
Zn.S65J*u
//count++; GmJ \3]{PZ
//if(count>4) zK1\InP
// siteStop(); i@WO>+iB
} 2uY:p=DxG9
xJ:Am>%\^
]v@ng8
System.err.println("文件下载结束！"); }3XjP55
} I Gb'ii=A
catch(Exception e){e.printStackTrace ();} QjJlVlp
} [a$1{[|)
xOg|<Nnl
@W(,|xES
//获得文件长度 jL5O{R[ x:
public long getFileSize() ^tm2Duv
{ Gv8Z
int nFileLength = -1; /i Xl]<
try{ 0L"uU3
URL url = new URL(siteInfoBean.getSSiteURL()); yJqDB$0
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); I 6<LKI/
httpConnection.setRequestProperty("User-Agent","NetFox"); R*W1<W%q=
wV$V X
_h=h43'3
int responseCode=httpConnection.getResponseCode(); L7(.dO0C
if(responseCode>=400) d@cyQFX
{ _3f/lG?&-
processErrorCode(responseCode); 1uA-!T*e>
return -2; //-2 represent access is error Ly, ];
} Ssa/;O2
^dxy%*Z/
5qqU8I
String sHeader; "4smW>f:%
j`3IizN2
o0b\<}
for(int i=1;;i++) B@\0b|
{ UQ^ )t ]
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); aG@GJ@w
//Utility.log(in.readLine()); >/@Q7V99{
sHeader=httpConnection.getHeaderFieldKey(i); B1i'Mzm-4
if(sHeader!=null) A"+t[0$.
{ 436SIh
if(sHeader.equals("Content-Length")) )F'hn+(B|G
{ 7A<}JaE!,
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); c-@EHv
break; pAN$c"
} T%}x%9VO7
} +{)V%"{u:
else ,(c'h:@M
break; l~kxK.Ru
} u6\W"LW
} \vj xCkg{
catch(IOException e){e.printStackTrace ();} s\3ZE11L
catch(Exception e){e.printStackTrace ();} P8CIKoKCV
<_bGV
=*y{y)B^g
Utility.log(nFileLength); b%X}{/n
#]}G{ P
L`^v"W()
return nFileLength; \jkDRR[
} 4=* ml}RP
:NH'>'
3i}$ ~rz]U
//保存下载信息（文件指针位置） _1$+S0G;
private void write_nPos() | 8n,|%e
{ yAel4b/}
try{ 0b,{4DOD
output = new DataOutputStream(new FileOutputStream(tmpFile)); :KRe==/
output.writeInt(nStartPos.length); 63i&e/pv
for(int i=0;i<nStartPos.length;i++) dUceZmAl
{ DshRH>7s8
// output.writeLong(nPos); E@="n<uS
output.writeLong(fileSplitterFetch.nStartPos); wLQM]$O
output.writeLong(fileSplitterFetch.nEndPos); (%M:=zm
} `5~<)
output.close(); /dVcNo3"
} D%'rq
catch(IOException e){e.printStackTrace ();} n^epC>a"b
catch(Exception e){e.printStackTrace ();} (G"/C7q
} [vCZD8"Y8
U:IeMf-;
:Sk<0VVd7
//读取保存的下载信息（文件指针位置） 3_ =:^Z
private void read_nPos() qRZLv7X*j
{ ,76nDXy`
try{ mO\=#Q>
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); a>nV!b\n5
int nCount = input.readInt(); r3Ih]|FK#
nStartPos = new long[nCount]; ve=1y)
nEndPos = new long[nCount]; D2#.qoP #
for(int i=0;i<nStartPos.length;i++) =1F F2#zS
{ ."v&?o Ck]
nStartPos = input.readLong(); ou&7v<)x4
nEndPos = input.readLong(); g[xn0rG
} y {Mh ?H
input.close(); $4TawFf"nc
} 2 BwpxV8
catch(IOException e){e.printStackTrace ();} v|>'m#Ln2
catch(Exception e){e.printStackTrace ();} @j4~`~8
} eJ$ {`&J
B;L^!sLP
W}oAgUd
private void processErrorCode(int nErrorCode) VoUAFEcs
{ X_I.f6v{
System.err.println("Error Code : " + nErrorCode); |<7nf75c}
} \6Hu&WHy
4\8k~#
W;wu2'
//停止文件下载 a,p7l$kK
public void siteStop() !1?Nc}T0Q&
{ z#|tl/aP9
bStop = true; (KG>lTdN
for(int i=0;i<nStartPos.length;i++) `\S~;O
fileSplitterFetch.splitterStop(); )'?@raB!
.J|"bs9
^`!EpO>k9
} iW<B1'dp
} ^S`c-N
//负责部分文件的抓取 Ibl==Irk
**FileSplitterFetch.java j6$_U@)%O
*/ b*qC
package NetFox; K<tkNWasQ
{R.@EFkZ
o#&;,9
import java.io.*; FY]z*=
import java.net.*; 30/(
%(wa~:m+S-
0bk094
public class FileSplitterFetch extends Thread { !ly]{DTmm
Eq/%k $6#1
G;pxB,4s5
String sURL; //File URL $X;fz)u
long nStartPos; //File Snippet Start Position X<"W@
long nEndPos; //File Snippet End Position |"a%S,I'
int nThreadID; //Thread's ID o%tvwv
boolean bDownOver = false; //Downing is over $PNIuC?=
boolean bStop = false; //Stop identical kQm\;[R
FileAccessI fileAccessI = null; //File Access interface enJE#4Z5&s
qu/59D
N;\by<snN
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException @7';bfsix
{ ojd/%@+u+Y
this.sURL = sURL; R|AGN*.
this.nStartPos = nStart; O ijG@bI8
this.nEndPos = nEnd; *tT}y(M
nThreadID = id; L$FLQyDR
fileAccessI = new FileAccessI(sName,nStartPos);//定位 r0\cgCn
} 'rdg
Nl1v*9_x
"VcG3.
public void run() t1 .6+
{ GVp2|\-L
while(nStartPos < nEndPos && !bStop) t=ry\h{Pc
{ < F Cr L
O<h`[1eUjS
X/nb7_M
try{ m:~s6c6H
URL url = new URL(sURL); iwfv t^
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); b-+iL
httpConnection.setRequestProperty("User-Agent","NetFox"); KdOy3O_5N
String sProperty = "bytes="+nStartPos+"-"; q-}J0vu\K
httpConnection.setRequestProperty("RANGE",sProperty); hQgi--Msw'
Utility.log(sProperty); BY$%gIB6>
R('44v5JQp
~Hs a6F&F
InputStream input = httpConnection.getInputStream(); ~z!U/QR2
//logResponseHead(httpConnection); _,;c2
!W8'apG&[
Aj4i}pT
byte[] b = new byte[1024]; &`63"^y
int nRead; X Jy]d/
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) _A\c 6#
{ (byFr9z
nStartPos += fileAccessI.write(b,0,nRead); '5eW"HGU]`
//if(nThreadID == 1) vV|u+v{
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 9oY%v7
} h7 >
p9 |r y+t
q$s0zqV5
Utility.log("Thread " + nThreadID + " is over!"); U:xr['
bDownOver = true; lG;sDR|)(
//nPos = fileAccessI.write (b,0,nRead); nMXSpX>!|
} =2{^qvP
catch(Exception e){e.printStackTrace ();} D{/GjFO
} C(_xqn
} u*&wMR>Crf
W!z=AL{
f?_H02j`/E
//打印回应的头信息 nlK"2/W
public void logResponseHead(HttpURLConnection con) -`B|$ W
{ uV*&a~
for(int i=1;;i++) #2&_WM!
{ jQ_j#_Vle
String header=con.getHeaderFieldKey(i); @QMMtfeLj
if(header!=null) 0=&Hm).
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ek#{!9-
Utility.log(header+" : "+con.getHeaderField(header)); jO$3>q
else Xi1/wbC
break; WrL&$dEJ?M
} F\&R nDJ
} [*#ms=Zdc
B}YB%P_CWs
z}N=Oe
public void splitterStop() _y),C
{ p}}o#a~V),
bStop = true; icHc!m?
} 4RNB\D
Hc4]2pf
cyG3le& +G
} Qg9 N?e{z
}0|,*BkI m
5B@+$D[0?3
/* o|AV2FM)
**FileAccess.java +=^10D
*//文件访问(定位，写) a4L8MgF&$-
package NetFox; $v+Q~\'
import java.io.*; L*1C2EL/q
`(EY/EsY
S!k cC-7
public class FileAccessI implements Serializable{ 3xh~xE
d?*=<w!A
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \:\rkc9LI
RandomAccessFile oSavedFile; sUcx;<|BC
long nPos; 9dr\=e6) C
z'MOuz~Y
u:3~Ius
public FileAccessI() throws IOException ZPY#<^WOzr
{ _CBG?
this("",0); [L"(flY(E
} Edc< 8-
J O`S
Lt.a@\J'_
public FileAccessI(String sName,long nPos) throws IOException jX!,xS%(
{ vz*QzVk1
oSavedFile = new RandomAccessFile(sName,"rw"); iXMs*GcK
this.nPos = nPos; ,l#Ev{
oSavedFile.seek(nPos); G0|j3y9$
} cWP34;NNM
m49GCo k+
`\P#TBM
public synchronized int write(byte[] b,int nStart,int nLen) [ K;3Qf)
{ {xp/1?Mo*
int n = -1; vZmM=hW~
try{ U|={LU
oSavedFile.write(b,nStart,nLen); ogH{
n = nLen; Lk6UT)C
} f3]Z22Yq
catch(IOException e) r:2G11[
{ DDyeNuK
e.printStackTrace (); V.6h6B!vB
} p@y?xZS
9H$#c_zrq
oEd+
return n; ?`,<l#sj
} >fPa>[_1
)"2)r{7:
vX;WxA<
} #TM+Vd$
nc!P !M
Wqy|Y*$qT
/* L]3 V)`}
**SiteInfoBean.java T$)&8"Xya
*/ +Fp8cT=1
package NetFox; Fx*iAH\e
H[UV]qO,
-uXf?sTV
public class SiteInfoBean { (;;%B=
*Fb]lM7D
+hI:5(_
private String sSiteURL; //Site's URL Va"Q1 *"
private String sFilePath; //Saved File's Path fgK1+sW
private String sFileName; //Saved File's Name +] >o@
private int nSplitter; //Count of Splited Downloading File d`q<!qFZh
`h}fS4CO
9q5jqFQ
public SiteInfoBean() _SC{nZ[
{//nSplitter的缺省值为5 )HQ':ZE$
//default value of nSplitter is 5 L\)ssOuh
this("","","",5); )-%3;e<w
} 9&}$C]`
U,Ya^2h%
&#^^UT(nj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) /]zn8d
{ j\iE3:94$
sSiteURL= sURL; bfcQ(m5
sFilePath = sPath; jT>G8}h
sFileName = sName; byoP1F%
this.nSplitter = nSpiltter; n]^zIe^6
ul$k xc=N
e`9d&"
} 5gYv CW&~
7yM=$"'d
~(OG3`W!
public String getSSiteURL() {Z0(V"Q
{ Yl4XgjG
return sSiteURL; Is1P,`*!
} ^)oBa=jL4
Cp4 U`]
ix2V?\
public void setSSiteURL(String value) *;cvG?V
{ :}'5'oVG
sSiteURL = value; vqO d`_)
} KT$Za
R8LJC]6Bh
_)-t#Ve
public String getSFilePath() fUj[E0yOF
{ dt&m YSZ}
return sFilePath; n-zAkKM
} T%74JRQ
]!CMo+
O(x1Ja,&
public void setSFilePath(String value) }huj%Pnk)
{ N~H!6N W
sFilePath = value; B'}h6ZH
} UMtnb:ek
ac
8J|2b; Vf
public String getSFileName() Nz/PAs7g6
{ x*>@knP<-
return sFileName; Qw>~]d,Z
} c12mT(+-
NxY B)`~
>TI/W~M
public void setSFileName(String value) r@")MOGc
{ (;\" K?
sFileName = value; [$\KS_,Mn
} B&:9uPRzZ
WH|TdU$V
gOiZ8K!
public int getNSplitter() ZHu"&&
{ >b\{y}[
return nSplitter; ;]v{3m
} u@&e{w~0
0O>T{<
U]/iPG&_
public void setNSplitter(int nCount) "x1?T+j4
{ Me;XG?`
nSplitter = nCount; /q1k)4?E
} N+lhztYQ?
} eX`wQoV%
}2xgm9j<
?D>%+rK8c
/* `JQw]\f4>
**Utility.java i~Qnw-^B
*/ UHyGW$B
package NetFox; /{6&99SJcc
&t)$5\r
jVlXB6[-
public class Utility { &{4KymB:
>]{{5oOQ>
/(oxK>*F
public Utility() 8*zORz
{ fQm3D%
/ R-1s
wjtFZGx&
} uNKf!\Y
+{~cX]|
//线程睡眠 %-?k [DL6
public static void sleep(int nSecond) ^%5;Sc1V
{ _tlr8vL
try{ tt&#4Z
Thread.sleep(nSecond); `d c&B
} /,d]`N!
catch(Exception e) \jmT#Gt`9
{ ?,}:)oA_
e.printStackTrace (); inHlL
} - +<ai
} h\T}$jgfWm
PGd?c#v#
//日志 !w1acmo<_
public static void log(String sMsg) >//yvkZ9,
{ M{z&h>
System.err.println(sMsg); &3Y"Zd!
} @[LM8 @:
nt:ZO,C:R
:(Ak:
public static void log(int sMsg) r\A|fiL
{ ppuJC'GW
System.err.println(sMsg); C>A} e6o
} qrHCr:~
} A&N$=9.N1
GvzaLEo
5Vc~yMz
/* 0VnRtLnqI
**TestMethod.java ZAJ~Tbm[f
*/ b{BiC&3
package NetFox; V=gu'~
(}RTHpD
lLur.f
public class TestMethod { 42f\]R,
TO&^%d
|F4)&xN\
public TestMethod() !_q=r[D\
{ ///xx/weblogic60b2_win.exe <<DPer2
try{ r}:Dg fn
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); P^aNAa
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); j];#=+
SiteFileFetch fileFetch = new SiteFileFetch(bean); EG8%X"p
fileFetch.start(); q*K[?
} ,\-4X
catch(Exception e){e.printStackTrace ();} 18^K!:Of
wG&Z7C b
|w"G4J6ha
} =}"P;4:
a8YFH$Xh
!a4`SjOgu
public static void main(String[] args) ')T*cLQ><
{ ]`q]\EH
new TestMethod(); y*Gq VA[
} ^V~^[Yp
} mg< v9#
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