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)); 9.&mz}q
} 7=k^M, a
for(int i=0;i<nEndPos.length-1;i++) L"vj0@n'0
{ ctI{^f:
nEndPos = nStartPos[i+1]; B8V,)rn
} qLjT.7 .x
nEndPos[nEndPos.length-1] = nFileLength; WRpyr
} `ZGcgO<c\
} K)[8 H~Lm
[ee30ELn
#I%s3
//启动子线程 nPA@h
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q~Ea8UT.#
for(int i=0;i<nStartPos.length;i++) #H5=a6E+q
{ g`?:=G:a*
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), V3.t;.@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), g1|w?pI1
nStartPos,nEndPos,i); CAgaEJhX3
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); A';QuWdT
fileSplitterFetch.start(); 213\ehhG<
} %Q4i%:Qi
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), SY _='9U
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); %l$W*.j|;
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", rK|*hcy
nEndPos = " + nFileLength); '6S%9ahE
// fileSplitterFetch[nPos.length-1].start(); J?Iq9f
BHr|.9g]%%
wk[ wNIu
//等待子线程结束 NQLiWz-q
//int count = 0; '3;v] L?G
//是否结束while循环 n?QZFeI`
boolean breakWhile = false; +)/Uu3"=
]~jN^"o_B
`X -<$x
while(!bStop) fN[8N$1-
{ ?<~WO?
write_nPos(); j_Nm87i]
Utility.sleep(500); ]WL|~mG
breakWhile = true; WS,7dz
>K:u?YD[
X")|Uw8Kl/
for(int i=0;i<nStartPos.length;i++) =`t^~.5
{ M-MKk:o
if(!fileSplitterFetch.bDownOver) ];FtS>\x
{ |wp,f%WK
breakWhile = false; |NMO__l@
break; x';uCKWV
} (S9f/i^
} jw>hk
if(breakWhile) AsxD}Nw[Z*
break; nhH;?D3
BIMKsF Zt
S`=WF^
//count++; *'8LntZf
//if(count>4) )K0i@hM(n
// siteStop(); X0uJNHO
} APSgnf
};katqzEg
j43$]'-
System.err.println("文件下载结束！"); S!Jh2tsg`-
} wAF,H8 -DK
catch(Exception e){e.printStackTrace ();} 6"QEJ
} 9M-K]0S(
wk$,k
Pe ~c
//获得文件长度 ]<trA$ 0
public long getFileSize() !G?gsW0\h
{ ?<%=: Yh
int nFileLength = -1; C/tr$.2H=
try{ EX "|H.(
URL url = new URL(siteInfoBean.getSSiteURL()); WES#ZYtT
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); wL{qD
httpConnection.setRequestProperty("User-Agent","NetFox"); r<R4 1Fz
bS^WhZy'(
Zi ESlf$
int responseCode=httpConnection.getResponseCode(); ?IhB-fd>@
if(responseCode>=400) 9F##F-%x
{ &|o$=Ad
processErrorCode(responseCode); [r-}bp'Gp
return -2; //-2 represent access is error Q!'qC*Gyfn
} !xK=#pa
uzU{z;
<"tDAx
String sHeader; I.jZ wW!r
*yaw$oB
raUs%Y3
for(int i=1;;i++) 3S~(:#|
{ SoQR#(73HK
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); gS9>N/b|
//Utility.log(in.readLine()); R.RSQk7;
sHeader=httpConnection.getHeaderFieldKey(i); |+f-h,
if(sHeader!=null) P~ 0Jg# V
{ \ v2H^j/
if(sHeader.equals("Content-Length")) FfFak@H
{ tw K^I6@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); $P {K2"Oc
break; !{UTD+|=N
} ,T5u'";
} uofr8oL~
else nb,2,H
break; =JO^XwUOo
} MQTdk*L_]
} 5W? PCOh\
catch(IOException e){e.printStackTrace ();} yI;"9G
catch(Exception e){e.printStackTrace ();} ;sOsT?)7$
@!%n$>p/V
_M5%V>HO
Utility.log(nFileLength); WNX5iwm
-K%5(Eg
X@wm1{!
return nFileLength; <PD?f/4 /
} E5GJi
}SfbCa)UO
})F*:9i*
//保存下载信息（文件指针位置） z~oDWANP
private void write_nPos() /f{$I
{ 9<1F[SS<s9
try{ )}lRd#V
output = new DataOutputStream(new FileOutputStream(tmpFile)); V%ii3
output.writeInt(nStartPos.length); !PUZWO
for(int i=0;i<nStartPos.length;i++) yW7'?
{ J./d!an
// output.writeLong(nPos); 2.I^Xf2
output.writeLong(fileSplitterFetch.nStartPos); lFG9=Wf
output.writeLong(fileSplitterFetch.nEndPos); RYR-K^;R
} Z*!O:/B
output.close(); ]ya; v '
} hlbvt-C?}"
catch(IOException e){e.printStackTrace ();} e{w>%)rcP
catch(Exception e){e.printStackTrace ();} &l2TeC@;
} U>qHn'M
tD=@SX'Y
2)0b2QbQ
//读取保存的下载信息（文件指针位置） 7L(eh7
private void read_nPos() @_ygnNn4R
{ ).412I
try{ sH#X0fG
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); hUpnI@
int nCount = input.readInt(); @tUoD>f
nStartPos = new long[nCount]; lx0~>K]
nEndPos = new long[nCount]; Rd&9E
for(int i=0;i<nStartPos.length;i++) ~qVz)<
{ 7{kP}?
nStartPos = input.readLong(); B|=|.qp$)
nEndPos = input.readLong(); (U1]:tZ<.
} #(;<-7M2
input.close(); wEft4o
} }M>rE
catch(IOException e){e.printStackTrace ();} fL*T3[d
catch(Exception e){e.printStackTrace ();} j f~wBmd7
} \FmKJ\
(#\pQ51
Zl/<w(f_
private void processErrorCode(int nErrorCode) r4}*l7Q
{ u0s8yPA
System.err.println("Error Code : " + nErrorCode); 5N7H{vT_
} AC%JC+
_c(4o:
AG6K daJ
//停止文件下载 CON0E~"
public void siteStop() NaUr!s
{ []kN16F
bStop = true; k\r(=cex6
for(int i=0;i<nStartPos.length;i++) MmTC=/j
fileSplitterFetch.splitterStop(); `RRE(SiKU
E;Y;r"
3.Gj4/f
} m6mwyom.
} 8P' ana
//负责部分文件的抓取 hcCp,b
**FileSplitterFetch.java !]` #JAL7
*/ A Io|TD5{~
package NetFox; wE\3$ s/{D
_banp0ywS
Ddju~510
import java.io.*; cu!W4Ub<
import java.net.*; _Xcn N:Rt
=}!Mf'
|J5 =J
public class FileSplitterFetch extends Thread { c"tJld5F_
uGU;Y'W)
'T=~jA7SkT
String sURL; //File URL RJeDEYXeg
long nStartPos; //File Snippet Start Position ef!XV7P
long nEndPos; //File Snippet End Position una%[jTc
int nThreadID; //Thread's ID wN-i?Ek0;
boolean bDownOver = false; //Downing is over R<ND=[}s
boolean bStop = false; //Stop identical %(/!ljh_
FileAccessI fileAccessI = null; //File Access interface 5~sx:0;
_,74)l1
'J)2g"T@
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException VhGs/5
{ q=Zr>I;(Ks
this.sURL = sURL; penlG36Q
this.nStartPos = nStart; -Ng'<7
this.nEndPos = nEnd; #EGA#SKoq
nThreadID = id; owpWz6k7
fileAccessI = new FileAccessI(sName,nStartPos);//定位 7}O.wUKw%
} [Qt?W gPj
2aA`f7
f$HH:^#
public void run() <|Yj%f
{ uQb!=]
while(nStartPos < nEndPos && !bStop) CI:^\-z
{ rX7QbAB
4M&`$Wim
V! |qYM.
try{ g.JN_t5
URL url = new URL(sURL); /.Nov
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); cXMhq<GkAA
httpConnection.setRequestProperty("User-Agent","NetFox"); f;SC{2f
String sProperty = "bytes="+nStartPos+"-"; IxR?'
httpConnection.setRequestProperty("RANGE",sProperty); hG~reVNf
Utility.log(sProperty); n(nBRCG)o
2f`nMW
5v)(8|.M
InputStream input = httpConnection.getInputStream(); 3l<S}k@M)
//logResponseHead(httpConnection); 'uDjFQX
5BkV aF7Th
. v@>JZC
byte[] b = new byte[1024]; 5F|8?BkOL^
int nRead; R=Ws#'
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) >gKh
{ q}BzyC=:n
nStartPos += fileAccessI.write(b,0,nRead); g @I6$Z
//if(nThreadID == 1) 'D1A}X
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); u,3,ck!B>@
} Do%-B1{ri
4n1; Bh$
Rv,JU6>i
Utility.log("Thread " + nThreadID + " is over!"); C${S^v
bDownOver = true; 8n BL\{'B[
//nPos = fileAccessI.write (b,0,nRead); kPBV6+d~
} p,pR!qC>
catch(Exception e){e.printStackTrace ();} ;|p$\26S)%
} Ch()P.n?
} Sw`RBN[ yo
:!;'J/B@..
;R=.iOn
//打印回应的头信息 @pI5lh
public void logResponseHead(HttpURLConnection con) x6afI<dm
{ zOEY6lAwI
for(int i=1;;i++) &bz:K8c
{ v1k)hFjPK
String header=con.getHeaderFieldKey(i); @=]~\[e\
if(header!=null) '/Bidb?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); aKUS5jDu
Utility.log(header+" : "+con.getHeaderField(header)); +t4BQf
else HBys
break; 9jp:k><\(c
} ~m1P_`T
} 5Ft5@UF~
5G0$
OX%MP!#KU
public void splitterStop() DcMJ^=r8O:
{ 6qe*@o
bStop = true; p_ Fy>j
} P+t#4J
jEc|]E
ri C[lB
} qjJBcu_C'S
1iL'V-y
%dErnc$
/* zJM S=r
**FileAccess.java -16K7yk
*//文件访问(定位，写) 04J}UE]Ww
package NetFox; E$a ?LFa6
import java.io.*; "M|P+A
P3 c\S[F
wpA`(+J
public class FileAccessI implements Serializable{ d_S*#/k
(vR 9H(#
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 4RKW
RandomAccessFile oSavedFile; ;)Kh;;e
long nPos; C=uZ1xg*,
krq/7|
y5= `ap
public FileAccessI() throws IOException jNwjK0?
{ 6b8;}],|
this("",0); .%'(9E
} k^$+n_
"I;C;}!
wn Y$fT9
public FileAccessI(String sName,long nPos) throws IOException c4e_6=Iv
{ c8)/:xxl
oSavedFile = new RandomAccessFile(sName,"rw"); $@\mpwANl
this.nPos = nPos; h@7FY
oSavedFile.seek(nPos); z|G9,:9
} _u"nvgVz9
3`O?16O
C\_zdADUb%
public synchronized int write(byte[] b,int nStart,int nLen) k&#a\OJ7u
{ ]DFXPV
int n = -1; NT%W;)6m9
try{ ;E~4)^
oSavedFile.write(b,nStart,nLen); ?6Cz[5\
n = nLen; "HD+rmUEH
} xy+QbDT
catch(IOException e) /Y[~-Y+!,
{ e]ig!G]
e.printStackTrace (); STfyCtS
} k)S.]!u&G
3`hUo5K
w)E@*h<Z
return n; [MX;,%;;
} {vaaFs
QVZD/shq
4A{|[}!
} +&tgJ07A
W-RqN!snJ8
2^~<("+w
/* Ot&:mT!2
**SiteInfoBean.java (VvKGh
*/ ZWc+),X
package NetFox; 0uVv<Q~
kI*(V[i
F}Mhs17!|
public class SiteInfoBean { @#+jMV$g
*, Ld/O;s
.=9s1~]
private String sSiteURL; //Site's URL I4H`YOD%
private String sFilePath; //Saved File's Path PZ:u_*Vu`
private String sFileName; //Saved File's Name XA0(f*
private int nSplitter; //Count of Splited Downloading File @ \.;b9
L^kp8o^$
VeiElU3
public SiteInfoBean() ydl jw
{//nSplitter的缺省值为5 (A k\Lm
//default value of nSplitter is 5 Ue5O9;y]u
this("","","",5); ir>]r<Zl
} '6Qy/R
pvWau1ArNq
)G^TW'9
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) u'Q?T7
{ #$S}3 o
sSiteURL= sURL; !}TMiCK
sFilePath = sPath; WiNT;v[
sFileName = sName; s}M= oe
this.nSplitter = nSpiltter; A)nW
<x%M3BTx
xIbMs4'iEx
} S{F-ttS"
KHiFJ_3
1ZJ4*bn
public String getSSiteURL() hi{%pi&!T
{ _cJ[ FP1
return sSiteURL; yT /EHmJ
} _68BP)nz>.
,1n >U?5
yFIy`9R
public void setSSiteURL(String value) MKGS`X]<J
{ UgHf*m
sSiteURL = value; *}b]rjsj
} e&Y0}oY
A//?6OJx?
l4'~}nn(Y
public String getSFilePath() cH`^D?#se
{ S*W;%J5
return sFilePath; -mNQ;zI1
} To"dG&h
*3{J#Q6fk3
-<f/\U
public void setSFilePath(String value) F%.xuLW
{ 'E]A.3-Mt
sFilePath = value; Dk)}|GJ()"
} 9V!-ZG
r((Tavn
Y)HbxFF`/
public String getSFileName() `"y`AY/N
{ \^532FIw6
return sFileName; nnCug
} 97~K!'/^+y
9Ld9N;rWm#
H3FW52pjX
public void setSFileName(String value) - V) R<
{ )*1.eObhL
sFileName = value; iLq#\8t^
} /0==pLa4
f@z*3I;
)^;DGzG
public int getNSplitter() >q( 5ir
{ U{1z;lJ
return nSplitter; Lyoor1
} =&U`9qN
hw,^G5m
SE`l(-tL
public void setNSplitter(int nCount) YB!!/ SX4
{ 2_pz3<,\
nSplitter = nCount; : }?{@#Z
} _vrWj<wyf
} 9{eBgdC
uEd,rEB>
'V!kL, 9ES
/* it}-^3AM
**Utility.java &4kM8Qh
*/ "bX4Q4Dq
package NetFox; 'h*Zc}Q:
#)74X%4(
981!2*
public class Utility { ])$S\fFm
Y6eEGo"K.+
{'~sS
public Utility() b=LF%P
{ g_ M-F
njMLyT($
p.Y$A if.
} a$+#V=bA
|=3 *;}
//线程睡眠 Z=9dMND
public static void sleep(int nSecond) 2LhE]O(_"
{ &%e"9v2`
try{ M {xie
Thread.sleep(nSecond); 3 jh|y,
} WEC-<fN|Y\
catch(Exception e) . bG{T|
{ 1URsHV!xcM
e.printStackTrace (); kPJ~X0Fr{t
} oNSz&)LP
} hEcYpng~
MZ^Ch
//日志 z(UX't (q
public static void log(String sMsg) r5)f82pQ
{ 7ukDS]
System.err.println(sMsg); Kq6qXc\x
} bX{PSjD
mh8nlB
m){&:Hs
public static void log(int sMsg) SA3Y:(
{ N[{]iQ
System.err.println(sMsg); Ja=N@&Z#
} ^z?=?%{
} JOHp?3"4
<w11nB)
+}]wLM}\UF
/* "b;k.Fx
**TestMethod.java ke</x+\F
*/ XAlD ww
package NetFox; bl9E&B/
<on)"{W13
;@O(z*14@
public class TestMethod { {r X5
~pwY6Q
?/L1tX)
public TestMethod() C$0ITw
{ ///xx/weblogic60b2_win.exe y7 <(,uT
try{ "p2u+ 8?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); _4S7wOq5
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z~B+*HF
SiteFileFetch fileFetch = new SiteFileFetch(bean); E<P*QZ-C3
fileFetch.start(); M,Po54u
} _"`/^L`Q?
catch(Exception e){e.printStackTrace ();} akY6D]M
n/:Z{
_c,&\ wl$
} F.&*D~f
,9+nfj
r]Z.`}Kkm
public static void main(String[] args) %hrsE5k^,
{ <`b|L9
new TestMethod(); %0go%_
} aw;{<?*
} ]*;RHy9
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