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)); B/a`5&G]
} Xykoq"dbb
for(int i=0;i<nEndPos.length-1;i++) ^"|q~2
{ #KoI8U"
nEndPos = nStartPos[i+1]; |g}r
} *GXPN0^Qjo
nEndPos[nEndPos.length-1] = nFileLength; HN367j2e
} Ln&~t(7
} Z+U -+eG
',`Qx{tQ)
aE)1LP
//启动子线程 `)8~/G%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; _GxC|d
for(int i=0;i<nStartPos.length;i++) f9#srIx+
{ {'+{ASpO!
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ,^e2ma|z
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), >2>/ q?
nStartPos,nEndPos,i); HN`qMGW^
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <& PU%^Ha
fileSplitterFetch.start(); sS{Co8EJn
} ^wZx=kas
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), tM\BO0
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); =PA?6Bm
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", t|oIzjKE/
nEndPos = " + nFileLength); hzqgsmT)
// fileSplitterFetch[nPos.length-1].start(); m,kYE9{
p+?`ru
;Ngk"5
//等待子线程结束 30WOH 'n
//int count = 0; "aKlvK:77
//是否结束while循环 .u ikte
boolean breakWhile = false; Y5CkCF
\8ZVI98
A/a=)su
while(!bStop) CB>W# P%
{ (|AZO!
write_nPos(); X(E`cH |
Utility.sleep(500); #]1jvB
breakWhile = true; |)>+& xk
%pxJ27Q
rlh:|#GTJ
for(int i=0;i<nStartPos.length;i++) y-H9fWi8Y&
{ EZiLXQd_
if(!fileSplitterFetch.bDownOver) P-T@'}lW
{ +`"Tn`O
breakWhile = false; |) ~-Wy
break; >G!=lLyR
} HP*{1Q@5
} *A48shfO
if(breakWhile) o<lmU8xB=
break; +UOVD:G
4Dzg r,V
P4yUm(@
//count++; {ly<%Q7j
//if(count>4) *%jtcno=Y
// siteStop(); 9xJtDdy-O
} ]Kjt@F";
J?#vL\8
7wWx8
System.err.println("文件下载结束！"); 5V(#nz
} dKEy6C"@
catch(Exception e){e.printStackTrace ();} w2b(,w
} (5Q<xJ
RgH 6l2
v9@_DlV\
//获得文件长度 Lbrn8,G\
public long getFileSize() (FGy"o%TP'
{ H1?C:R
int nFileLength = -1; #'f5owk>,
try{ ddl]! ^IK
URL url = new URL(siteInfoBean.getSSiteURL()); $A5O>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Kp7)my
httpConnection.setRequestProperty("User-Agent","NetFox"); X4\T=Q?uLx
Or$"f3gq
?1r;6
int responseCode=httpConnection.getResponseCode(); QPp31o.!5
if(responseCode>=400) ~eP~c"L
{ JP"#9f
processErrorCode(responseCode); Xsanc@w)^C
return -2; //-2 represent access is error HhCFAq"j
} KY< $+/B!
$$p +~X
jdVj FCl^#
String sHeader; 1Z_w2D*
QhTn9S:D
{G3Ok++hc
for(int i=1;;i++) 5ad@}7&
{ _-{=Z=?6}
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 1+3-Z>^e
//Utility.log(in.readLine()); 3TjyKB *!
sHeader=httpConnection.getHeaderFieldKey(i); dzbbFvG
if(sHeader!=null) :8bq0iqsV
{ \>"Zn7
if(sHeader.equals("Content-Length")) 7~1Fy{tc
{ Rq2bj_j
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); h*<`ct xL
break; .#tA .%
} !a V:T&6
} N@Ap|`Ei
else T:%0i8p
break; Z?[R;V1j
} KMfIp:~
} 4Hyp]07
catch(IOException e){e.printStackTrace ();} )D+eWo
catch(Exception e){e.printStackTrace ();} =s:kC`O
m7A3i<6p
\N|}V.r
Utility.log(nFileLength); hB>FJZQ_
e 5(|9*t
)~$ejS
return nFileLength; @HI@PZ>
} ! B`
|Om][z
hqHk,#
//保存下载信息（文件指针位置） K0'p*[yO/j
private void write_nPos() @$p6w
{ Y*lc ~X
try{ "IJ1b~j?
output = new DataOutputStream(new FileOutputStream(tmpFile)); )2d1@]6#
output.writeInt(nStartPos.length); %2'4h(Oq^
for(int i=0;i<nStartPos.length;i++) nip*Y@-F
{ <ldArZ4C4
// output.writeLong(nPos); "\~>[on
output.writeLong(fileSplitterFetch.nStartPos); M`=\ijUwN
output.writeLong(fileSplitterFetch.nEndPos); Fm&f
} '>bn94$
output.close(); F|VHr@%
} i 28TH Jh
catch(IOException e){e.printStackTrace ();} K",Xe>
catch(Exception e){e.printStackTrace ();} v'`qn
} %,S:^Rvv
(IHR {m
F!I9)PSj
//读取保存的下载信息（文件指针位置） (?T{^Hg
private void read_nPos() 3-;<G
{ SFP?ND+7
try{ . Z9c.E{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); $i3`cX)g
int nCount = input.readInt(); bFA lC
nStartPos = new long[nCount]; y~t e!C
nEndPos = new long[nCount]; "f3mi[
for(int i=0;i<nStartPos.length;i++) f@Ve,i
{ h{~GzrL*
nStartPos = input.readLong(); NN:zQ_RT
nEndPos = input.readLong(); 2=7[r-*E
} :c}PW"0v
input.close(); h6`VU`pPI
} \Yv44*I`
catch(IOException e){e.printStackTrace ();} mH<|.7~0
catch(Exception e){e.printStackTrace ();} Yu[MNX;G
} *ZRk)
6khm@}}
W8]?dL}|
private void processErrorCode(int nErrorCode) Qe9}%k6@E
{ F5UHkv"K&O
System.err.println("Error Code : " + nErrorCode); [ f<g?w
} 4w 7vgB
.",BLuce
b?M. 0{"H
//停止文件下载 6|6O| <o
public void siteStop() $`C$|9S
{ cI7aTLC"s
bStop = true; }LWrtmc
for(int i=0;i<nStartPos.length;i++) :.-KM7tDI1
fileSplitterFetch.splitterStop(); L&5zr_
m+pK,D~{"
5ry[Lgg
} Z\1`(Pq7`
} 0!axAvBV
//负责部分文件的抓取 mxc^IRj
**FileSplitterFetch.java Z0V6cikW6
*/ 54s90
package NetFox; 0(uba3z
sG|,#XQ
gV5mERKs
import java.io.*; rb>2l3g*
import java.net.*; &MONg=s3
p .~5k
`Y '-2Fv
public class FileSplitterFetch extends Thread { %3K'[2F
?IO3w{fmH
>;xkiO>Y
String sURL; //File URL !0X"^VB
long nStartPos; //File Snippet Start Position K_X(j$2Xc
long nEndPos; //File Snippet End Position h9. Yux
int nThreadID; //Thread's ID Sn;q:e3i{A
boolean bDownOver = false; //Downing is over nu16L$]
boolean bStop = false; //Stop identical BMU#pK;P]
FileAccessI fileAccessI = null; //File Access interface pqbKPpG
4]cr1K ^
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException `V[ hE r|
{ q^[SN
this.sURL = sURL; 0|rdI,z
this.nStartPos = nStart; IPY[x|
this.nEndPos = nEnd; q6 4bP4K
nThreadID = id; bh5C
fileAccessI = new FileAccessI(sName,nStartPos);//定位 y<yU5
} AX{yfL
Ojp|/yd^YL
iA"H*0
public void run() #vcQ =%;O
{ SR/ "{\C
while(nStartPos < nEndPos && !bStop) s*>B"#En
{ DK%@[D
bde6 ;=oM
Y$ZDJNz
try{ m?1AgsBR
URL url = new URL(sURL); uKT\\1Jrq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); {~=gKZ:-@
httpConnection.setRequestProperty("User-Agent","NetFox"); D rouEm
String sProperty = "bytes="+nStartPos+"-"; yyjgPbLN=
httpConnection.setRequestProperty("RANGE",sProperty); 61z^(F$@
Utility.log(sProperty); Wb{8WPS
**n109R
Q>/[*(.Wd
InputStream input = httpConnection.getInputStream(); %BkPkQA
//logResponseHead(httpConnection); C9`x"$
s:sk`~2<gd
).r04)/
byte[] b = new byte[1024]; g$Nsu:L
int nRead; pA5X<)~
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) YtT:\#D
{ B o[aiT
nStartPos += fileAccessI.write(b,0,nRead); G4f%=Z
//if(nThreadID == 1) `]l[p+DO
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); {/qq*0wa
} 9q<?xO
pH.&OW%
I}/-zyx>=
Utility.log("Thread " + nThreadID + " is over!"); Z&y9m@
bDownOver = true; /}-LaiS
//nPos = fileAccessI.write (b,0,nRead); &?SU3@3|
} O#b%&s"o
catch(Exception e){e.printStackTrace ();} [PU0!W;
} 'A#l$pJp7
} #_fL[j&
,09d"7`X
=Wl}Pgo!
//打印回应的头信息 fh}j)*K8
public void logResponseHead(HttpURLConnection con) |uln<nM9
{ H:L<gv(rG
for(int i=1;;i++) =q*j". <
{ v6KF0mqA&
String header=con.getHeaderFieldKey(i); 4ko(bW#jL
if(header!=null) =a./HCF
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 7Dx<Sr!
Utility.log(header+" : "+con.getHeaderField(header)); E`UEl$($
else nOUF<DNQ
break; !\1Pu|
} O<qo%fP
} 6y)NH 8l7
GMoE,L
@EB2I+[
public void splitterStop() C?VNkBJ>\
{ d}]jw4
bStop = true; K<ok1g'0
} >[gNQJ6
Q|:qs\6q5
[e`6gGO
} THDyb9_g
dht*1i3v
g%f6D%d)A
/* <>6DPHg~
**FileAccess.java 6J%yo[A(w
*//文件访问(定位，写) $#F7C[2N
package NetFox; 7 a_99?J
import java.io.*; \TXCq@
#R3|nL
yj C@
public class FileAccessI implements Serializable{ f^kH[C
dn@_\5
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 Lkl^ `
RandomAccessFile oSavedFile; Mi&jl_&
long nPos; TbA=bkj[4
\ POQeZ
X=i",5;
public FileAccessI() throws IOException |4|j5<5
{ /%w3(e
this("",0); c0u1L@tj
} "AUHe6Yv
.=<<b|
$fl+l5?9
public FileAccessI(String sName,long nPos) throws IOException a EmLf
{ ,fW%Qv
oSavedFile = new RandomAccessFile(sName,"rw"); C{8(ew
this.nPos = nPos; z1 P=P%F
oSavedFile.seek(nPos); rRzc"W}K+
} OtFGo8
&i?>mt
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public synchronized int write(byte[] b,int nStart,int nLen) $z5
{ r;cILS|Xr
int n = -1; }IGoPCV|
try{ j$Z:S~*
oSavedFile.write(b,nStart,nLen); YPNG9^Y
n = nLen; IG=#2 /$
} :J6lJ8w ?
catch(IOException e) $c<NEt_\
{ U[t/40W}P
e.printStackTrace (); xb~8uD5
} @j|=M7B
c 1o8
6@; P
return n; #:LI,t
} d| OEZx
%d"d<pvx
C6{\^kG^j2
} 5>u,Qh
NANgV~Y&
k~=_]sLn
/* *'jI>^o
**SiteInfoBean.java 5VR=D\j
*/ qz6@'1
package NetFox; DA wUG
dcbE<W#ss
{YigB
public class SiteInfoBean { pa8R;A70Dl
hX9vtV5L
H^r;,Q$9
private String sSiteURL; //Site's URL JOFQyhY0>m
private String sFilePath; //Saved File's Path g?i0WS
private String sFileName; //Saved File's Name "9bd;Tt:
private int nSplitter; //Count of Splited Downloading File vkE a[7
]<Kkq!
"';K$&,[
public SiteInfoBean() *~SanL\
{//nSplitter的缺省值为5 Q.Xs%{B
//default value of nSplitter is 5 LZH~VkK@m}
this("","","",5); {q1u[T&r
} fobnK~2
@Tz}y"VG
[H5BIM@{
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) $~5ax8u&!#
{ Dlqvz|X/
sSiteURL= sURL; "cDMFu
sFilePath = sPath; 5e}adHjM
sFileName = sName; q)PLc{NO
this.nSplitter = nSpiltter; Bx9v2x.
d.Ep#4
GLWEoV9<
} $@^*lUw
v1}9i3Or#
B3g#)
public String getSSiteURL() <e'/z3TbRW
{ L-eO_tTh0
return sSiteURL; <@H`5[R
} _2 oZhJ
s&7TARd
DrA\-G_7
public void setSSiteURL(String value) (j?ckah%V
{ v@ifB I
sSiteURL = value; JpE7"Z"~MS
} T7R,6qt
n4InZ!)
p!>DA?vF
public String getSFilePath() /^hc8X
{ Aa4 DJ
return sFilePath; r&3EM[*Iw
} %fMFcL#h
R1vuf*A5,
*%CDQx0}
public void setSFilePath(String value) &t:~e" 5<
{ <N{Y*,^z
sFilePath = value; }?^]-`b
} d}Xb8SaE%c
lsA?|4`mn
%sCG}? y
public String getSFileName() sWv!ig_
{ keb.%cb=
return sFileName; = P$Q;d
} W$xW9u8@+(
F4PWL|1
t Z@OAPRx
public void setSFileName(String value) +vt?3i\^.
{ :hTmt{LjN
sFileName = value; 2@,rIve
} EslHml#
N"8'=wB
Y^tUcBm\
public int getNSplitter() ;a 6Z=LB
{ [*U.bRs
return nSplitter; =z zmz7op
} `Z^\<{z
[JYy
P&IS$FC.\
public void setNSplitter(int nCount) IoZ_zz0
{ bF'Jm*f
nSplitter = nCount; DT3"uJTt
} ~,7Tj
} %>!W+rO,
x%W%
X`28?
/* Yk0/f|>O
**Utility.java +CN!3(r
*/ ~9Qd83`UH
package NetFox; M>d^.n
6TDa#k5v
_B0C]u3D
public class Utility { 'x6rU"e$J
GT,1t=|&V
'| p"HbJ
public Utility() L~Y^O`c
{ jo' V.]\
o .*t
t:"%d9]
} P'^& SK
MM6PaD{
//线程睡眠 -"rANP-UI
public static void sleep(int nSecond) ^hcK&
{ '^`iF,rg
try{ wZVLpF+7
Thread.sleep(nSecond); XT?wCb41R
} Clb7=@f
catch(Exception e) Nq1YFI>W
{ ,P%i%YPj
e.printStackTrace (); t;`ULp~&
} /ke[nr
} Z7>Nd$E{
m48Ab`
//日志 6O_l;A[=1
public static void log(String sMsg) "B>8on8O
{ CEAmb[h
System.err.println(sMsg); aNBwb9X
} qu&p)*M5
$]rC-K:Z
45k.U$<|
public static void log(int sMsg) <}T7;knO
{ Yv.7-DHNl
System.err.println(sMsg); g7{:F\S
} dQ_hlx!J
} EQ.K+d*K][
P *&Cght>0
my0iE:
/* 9N<=,!;5~s
**TestMethod.java 4'TssRot@h
*/ Lp(i&A
package NetFox; I4KE@H"%7
aW}d=y[
@_wJN Qo`
public class TestMethod { P9 HKev?y
nG4ZOx.*1g
IH=$ wc
public TestMethod() XcT!4xG0
{ ///xx/weblogic60b2_win.exe (/$-2.@
try{ pnSKIn
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _D}3``
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Ojz'p5d`>
SiteFileFetch fileFetch = new SiteFileFetch(bean); T1$p%yQH
fileFetch.start(); (" :Dz_
} `Gv\"|Gn
catch(Exception e){e.printStackTrace ();} rK'Lvt@w
b||usv[or
kCD]&
} #&)H&H}
pW.WJ`Rk
octQ[QXo#
public static void main(String[] args) qvu1u GCc
{ v)*MgfS
new TestMethod(); =&08s(A
} 4>oM5Yf8
} TaSS) n
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