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)); Bbb_}y|CA
} zSpL^:~
for(int i=0;i<nEndPos.length-1;i++) NaR/IsN8%
{ 8op,;Z7Y
nEndPos = nStartPos[i+1]; ugZ-*e7
} HW{si]~q
nEndPos[nEndPos.length-1] = nFileLength; ,r&:C48dI
} Eagl7'x
} "I)*W8wTn
dKOW5\H'
[_jd
//启动子线程 8f^QO:
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; (dL;A0L
for(int i=0;i<nStartPos.length;i++) 63J_u-o
{ XzX-Q'i=n0
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ;Y&<psQeb
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1kiS."77x
nStartPos,nEndPos,i); k,~I>qg
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); HF3W,eaqK
fileSplitterFetch.start(); QWo_Zg0"
} xHA6
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ] Q 'Ed
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 7 +RsZu
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", [a\U8 w
nEndPos = " + nFileLength); vS! TnmF
// fileSplitterFetch[nPos.length-1].start(); :V(+]<
7rc6
jLANv{"
//等待子线程结束 w3l+BUn:X
//int count = 0; lw.4O^
//是否结束while循环 FD}hw9VyF@
boolean breakWhile = false; d!V;\w
[r_YQ*+ej
^!={=No]
while(!bStop) H%!ED1zpA
{ m.F \Mn
write_nPos(); ZB+N[VJs)
Utility.sleep(500); kl0!*j
breakWhile = true; ;3nR_6\
<Ae1YHUY
:'L^zGf
for(int i=0;i<nStartPos.length;i++) MH"{N "|
{ Mw0Kg9M
if(!fileSplitterFetch.bDownOver) #E[{
{ 6D[m}/?Uy
breakWhile = false; uafSz@`
break; ICJp-
} xKilTh_.6
} ?!N@%R>5rN
if(breakWhile) hdi/k!9[\
break; d"E@e21
Mr5E\~K>s
@~4Q\^;NX
//count++; e?Pzhha
//if(count>4) 5 A/[x$q
// siteStop(); Fk:yj 4'
} %gF; A*
!>~W5c^
!+&Rn\e%7
System.err.println("文件下载结束！"); b(hnouS
} WUVRwJ 5
catch(Exception e){e.printStackTrace ();} 5h"moh9tG
} ZyJdz+L{@V
-Y*"!8
iIOA54!o
//获得文件长度 ])d_B\)Kck
public long getFileSize() ~1x,m.f8
{ `/zx2Tkk
int nFileLength = -1; a(+.rf;
try{ k`LoRqF
URL url = new URL(siteInfoBean.getSSiteURL()); W?a{3B
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j@JhxCe1+R
httpConnection.setRequestProperty("User-Agent","NetFox"); uR|?5DK
6Un61s
-h5yg`+1N\
int responseCode=httpConnection.getResponseCode(); Q(P'4XCm
if(responseCode>=400) th@a./h"
{ 6x1!!X+)+
processErrorCode(responseCode); .qjVw?E
return -2; //-2 represent access is error s0}OsHAj
} @yBg)1AL
7pB5o2CD0
*Q?ZJS~
String sHeader; =j%B`cJ66_
bB|UQaCl
.hYrE5\-
for(int i=1;;i++) `+IB;G1
{ 6g/ <FM
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 2>l =oXq
//Utility.log(in.readLine()); ~$#"'Tl4J
sHeader=httpConnection.getHeaderFieldKey(i); (dOC ^i
if(sHeader!=null) 1_D|;/aI
{ QZcdfJck=+
if(sHeader.equals("Content-Length")) ]9xuLJ)
{ '@Zau\xC
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); B8+J0jdg6%
break; q Ee1OB
} 8.-0_C*U;
} w\ hl2JTy
else pYtG%<
break; 4!'1o`8vs
} c7$L:
} )7U^&I,
catch(IOException e){e.printStackTrace ();} sSisO?F!Z
catch(Exception e){e.printStackTrace ();} D&Xh|}2A
q[6tvPfkX
H%,jB<-.A
Utility.log(nFileLength); w2-:!,X
<ptgFR+
m/,.3v
return nFileLength; gy|L!_1Z8
} QXXB>gOY5
s}MD;V&0
1Sk=;Bic
//保存下载信息（文件指针位置） l(-We.:(
private void write_nPos() C- Aiv@@<=
{ Xb0$BAP
try{ 72hN%l
output = new DataOutputStream(new FileOutputStream(tmpFile)); #;9I3,@/Y
output.writeInt(nStartPos.length); ?2hS<qXX
for(int i=0;i<nStartPos.length;i++) ^[K3]*!@
{ r-M:YB
// output.writeLong(nPos); +.Pv:7gh
output.writeLong(fileSplitterFetch.nStartPos); {Y>5 [gp
output.writeLong(fileSplitterFetch.nEndPos); GZxM44fP
} a;=)`
output.close(); 6jv_j[[
} d~bZOy
catch(IOException e){e.printStackTrace ();} XLEEd?Vct9
catch(Exception e){e.printStackTrace ();} {!? @u?M
} U(lcQC`$
~U] "dbQ
wul$lJ?tE
//读取保存的下载信息（文件指针位置） K?;_T$^K
private void read_nPos() BCDmce`=l
{ $XBn:0U
try{ tUS)1*{_
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ]V|rOtxb
int nCount = input.readInt(); 3[R<JrO
nStartPos = new long[nCount]; ^/nj2"
nEndPos = new long[nCount]; }ll&qb
for(int i=0;i<nStartPos.length;i++) W'aZw9
{ UKYQ @m
nStartPos = input.readLong(); F32N e6Y6"
nEndPos = input.readLong(); 8v$2*$
} XJx$HM&0M
input.close(); N?xZ]?T
} )e#KL$B)v
catch(IOException e){e.printStackTrace ();} =fJDFg
catch(Exception e){e.printStackTrace ();} !Zowe*`
} PUt\^ke
C$"N)6%q
Y(aEp_kV
private void processErrorCode(int nErrorCode) !+sC'/
{ #6t 4 vJ1
System.err.println("Error Code : " + nErrorCode); /z<7gd~oU
} 9q +I
@DiXe[kI
J1i{n7f=@
//停止文件下载 pbfIO47ZC
public void siteStop() f`ro{p
{ [I*)H7pt}
bStop = true; w %4SNR
for(int i=0;i<nStartPos.length;i++) p>4tPI}bf
fileSplitterFetch.splitterStop(); gYeKeW3)
*QKxrg
]!7%)
} ?]*WVjskE
} 9CBKU4JQ
//负责部分文件的抓取 r7Vt,{4/
**FileSplitterFetch.java t>hoXn^-
*/ 5yOIwzr&Uu
package NetFox; t0*kL.
fQW1&lFT
se|>P=/
import java.io.*; 1M1|Wp
import java.net.*; `IP?w&k)
\a<7DTV
e"Y ( 7<
public class FileSplitterFetch extends Thread { :;Lt~:0b~
CbvP1*1
[Lck55V+Q
String sURL; //File URL v'Y0|9c
long nStartPos; //File Snippet Start Position &a;{ed1B
long nEndPos; //File Snippet End Position !,Ou:E?Bb
int nThreadID; //Thread's ID uDtml$9rN
boolean bDownOver = false; //Downing is over nt 9LBea
boolean bStop = false; //Stop identical zd%n)jlwR
FileAccessI fileAccessI = null; //File Access interface :B^YK].
X;e=d+pw
A-n@:` n~
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException Mi>!
{ ZmLA4<
this.sURL = sURL; pZE}<EX
this.nStartPos = nStart; QN4{xf:}S
this.nEndPos = nEnd; BlLK6"gJT
nThreadID = id; .uh>S!X, ]
fileAccessI = new FileAccessI(sName,nStartPos);//定位 ]%%I=r
} Z\YCjs%
B$=oU
Ow#a|@
public void run() ]_"c_QG
{ X!aC6gujOH
while(nStartPos < nEndPos && !bStop) @AB}r1E2
{ _i3?;Fds
M]Kxg;
tPp9=e2[s
try{ :VkuK@Th`
URL url = new URL(sURL); ;[qA?<GJ
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <?2g\+{s9
httpConnection.setRequestProperty("User-Agent","NetFox"); CXQ+h
String sProperty = "bytes="+nStartPos+"-"; 5dvP~sw
httpConnection.setRequestProperty("RANGE",sProperty); WyA`V C
Utility.log(sProperty); !W\za0p
o+],L_Ab
{yzo#"4Oy
InputStream input = httpConnection.getInputStream(); |o@xWs@m
//logResponseHead(httpConnection); Y>J$OA:
q1a*6*YB
T`zUgZ]
byte[] b = new byte[1024]; x/S:)z%X
int nRead; z|M+ FHl$
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) C vOH*K'
{ >g>L>{
nStartPos += fileAccessI.write(b,0,nRead); T1-.+&<
//if(nThreadID == 1) \ u*R6z
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [ML|,kq!
} ;aj4V<@
.OM^@V~T
A"3"f8P8a
Utility.log("Thread " + nThreadID + " is over!"); 3(oB[9]s
bDownOver = true; J16t&Ha`
//nPos = fileAccessI.write (b,0,nRead); B>;`$-
} +s j2C
catch(Exception e){e.printStackTrace ();} .),Fdrg
} 1!S*z^LGl
} ;f!}vo<;
(y^svXU}a
SG4)kQ
//打印回应的头信息 ?wi^R:2|j
public void logResponseHead(HttpURLConnection con) )MWbZAI
{ yC:C
for(int i=1;;i++) qNuBK6E#4
{ I.6 qA *
String header=con.getHeaderFieldKey(i); , 3&DA
if(header!=null) D7lRZb
//responseHeaders.put(header,httpConnection.getHeaderField(header)); oypF0?!m
Utility.log(header+" : "+con.getHeaderField(header)); 4=nh' U38
else >ufLRGL>
break; V[;^{,;
} u|+Dqe`
} #rI4\K
)p`zN=t
<~bvfA=
public void splitterStop() ;%Zu[G`C
{ Z#t}yC%^d
bStop = true; o.g)[$M8cF
} 01<Ti"
K'c[r0Ew
Vr7L9%/wg
} I_s*pT
4n0Iw I
Krd0Gc~\|
/* wBlo2WY
**FileAccess.java ;S?ei>Q
*//文件访问(定位，写) 1>=]lMW
package NetFox; mVd%sWD
import java.io.*; K2qKkV@
P,s>xM
ce<88dL
public class FileAccessI implements Serializable{ xUF5
B!x7oD9
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 5hl!zA?
RandomAccessFile oSavedFile; #|QA_5
long nPos; j a'_syn
|/%X8\
S[e> 8
public FileAccessI() throws IOException zi_0*znw
{ {U)q)
this("",0); yIu_DFq%
} a_\t(U
O?f?{Jsx
u\3=m%1
public FileAccessI(String sName,long nPos) throws IOException -`CE;
{ {%D4%X<
oSavedFile = new RandomAccessFile(sName,"rw"); ':7gYP*v
this.nPos = nPos; Y~B-dx'V
oSavedFile.seek(nPos); d$HPpi1LL
} ATF>"Ux
w\1K.j=>|N
lNo]]a+_
public synchronized int write(byte[] b,int nStart,int nLen) x"P@[T
{ qK)T#sh
int n = -1; g!;a5p6
try{ zwJ\F '
oSavedFile.write(b,nStart,nLen); /[I#3|
n = nLen; J%IKdxa
} owzcc-g
catch(IOException e) R9-Uoc/
{ 9*S9~
e.printStackTrace (); cDq*B*e
} 0"l`M5-KP
+' SG$<Xv
&<EixDi4q
return n; &&7&/
} 07G'"=
r<[G~n
hf:\^w
} T*%O\&'r
v+~O\v5Q
"I QM4:
/* x~E\zw
**SiteInfoBean.java E/2_@&U:}
*/ `Krk<G
package NetFox; y=2nV
m>f8RBp]'
0|| 5r#
public class SiteInfoBean { 32p9(HQ
,rX|_4n*
@!*I mNMI
private String sSiteURL; //Site's URL 0.&-1pw
private String sFilePath; //Saved File's Path ;!B,P-Z"g
private String sFileName; //Saved File's Name bb}Fu/S
private int nSplitter; //Count of Splited Downloading File _2WW0
A$n:
<m> m"|G
public SiteInfoBean() 5nXmaj
{//nSplitter的缺省值为5 t4UL|fI
//default value of nSplitter is 5 V6&6I
this("","","",5); J;N\q
} ~!P&LZ
F{E`MK~f_
j9R+;u/!
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) RBpv40n0
{ k54b@U52 h
sSiteURL= sURL; pp+z5
sFilePath = sPath; _adW>-wQ!d
sFileName = sName; Y/f8rN
this.nSplitter = nSpiltter; Zfd `Fu
v,Z?pYYo
x b!&'cw
} s=Xg6D
Ap> H-/C
l6N"{iXU
public String getSSiteURL() SP;1XXlL
{ aWY#gI{
return sSiteURL; k{ulu
} &kQj)
P"|-)d
|Y30B,=M
public void setSSiteURL(String value) ^nLk{<D35
{ ~&WBA]w'+
sSiteURL = value; *9US>mVy
} |=[._VH1
@xr}(.
jP.dQj^j&
public String getSFilePath() G[]h1f!
{ v)~!HCG
return sFilePath; 2BO"mc<#$
} 7 b{y
XdE|7=+s
s0'6r$xj
public void setSFilePath(String value) SP4(yJy&
{ P&Wf.qr{:
sFilePath = value; YoSBS
} X$=/H 6R5Z
]+Z,HY@;-
>6|Xvtf
public String getSFileName() %?J-0
{ ZQyXzERp
return sFileName; B;t{IYhq{
} (d['f]S+&
|eksvO'~
+*G<xW :M
public void setSFileName(String value) $\L=RU!c}
{ j07b!j:"\}
sFileName = value; } a!HbH
} cHJ4[x=
Y8/&1s_
u6 4{w,
public int getNSplitter() p+CK+m
{ pwl7aC+6d
return nSplitter; ufN`=IJ%
} x5k6"S"1,
`82^!7!
"YN6o_*]
public void setNSplitter(int nCount) dK]#..
{ o[g]Va*8
nSplitter = nCount; ue -a/a
} G*g*+D[HM
} WyUa3$[gO
&<# ,J4
jWK>=|)=c
/* 54Vb[;`Kkb
**Utility.java n66b(6"mO2
*/ UW&K\P
package NetFox; Mr@{3do$
c LfPSA
E0eZal],
public class Utility { Dk}txw}#
5KW n>n
6>[J^k%~w)
public Utility() CIQ9dx7>
{ G5UNW<P2C
v%S$5
-pQ0,/}K
} uCj)7>}v{M
2,p= %
//线程睡眠 IeB^BD+j
public static void sleep(int nSecond) V5+|H1=
{ 9L>ep&u)^
try{ uExYgI`<%&
Thread.sleep(nSecond); [pz1f!Wn
} v"dl6%D"
catch(Exception e) B \.05<
{ US&:UzI.
e.printStackTrace (); B~%SB/eu
} B]PG
} FB O_B
wdRk+
//日志 >viLvDng
public static void log(String sMsg) o:@A%*jg
{ VW:Voc
System.err.println(sMsg); >|hqt8lY
} Agwl2AM5k
Pk^V6-
fjHd"!)3
public static void log(int sMsg) )SfM`W)Y
{ >ajcfG.k(
System.err.println(sMsg); D"P<;@ef
} o'ZW
} :-j/Y'H_
qR^+K@*|
C`\yc_b9Pf
/* -IL' (vx
**TestMethod.java {%z5^o1)
*/ 7/bF04~%
package NetFox; la{o<||Aq
lht :%Ts$
`91?^T;\F
public class TestMethod { l(~NpT{=V
z[0t%]7l
($[@'?Z1
public TestMethod() _:G>bU/^
{ ///xx/weblogic60b2_win.exe Yz>8 Nn'_
try{ ZU5;w
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); V""3#Tw
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); SKJ'6*6
SiteFileFetch fileFetch = new SiteFileFetch(bean); sfC/Q"Zs
fileFetch.start(); #ihHAiy3
} uC"Gm;0
catch(Exception e){e.printStackTrace ();} 8e_9u@p+w
||#+ ^p7G
(o!i9)
} K# h7{RE
RYM[{]4b5F
/[|A(,N}{
public static void main(String[] args) ?aU-Y_pMe
{ E>kgEfzxP
new TestMethod(); UL3u2g;d
} e_llW(*l8^
} #G("Oh
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