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)); yM ,VrUh
} <%KUdkzEP
for(int i=0;i<nEndPos.length-1;i++) ? )_7U
{ ^ ulps**e
nEndPos = nStartPos[i+1]; K-(;D4/sQE
} 7'OPjtM
nEndPos[nEndPos.length-1] = nFileLength; H$tb;:
} 5v9uHxy
} N9]xJgTze
4ht\&2&:
uyT/Xzo3
//启动子线程 Rp/-Pv
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 2B` 8eb
for(int i=0;i<nStartPos.length;i++) \r;F2C0*i
{ FH*RU1Z
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ]XUSqai
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), l1<?ONB.#
nStartPos,nEndPos,i); GwQn;gkF
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); $]*d#`Sy{%
fileSplitterFetch.start(); ~/|zlu*jpc
} Mm#[&j[Y
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), gs`> C(
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [5Y<7DS
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", <&U!N'CE
nEndPos = " + nFileLength); (WE,dY+.
// fileSplitterFetch[nPos.length-1].start(); }-p,iTm
zu<3^=3
;'3]{BGcU
//等待子线程结束 $Ha%Gr
//int count = 0; |Q!4GeQL[
//是否结束while循环 p)/ p!d[T/
boolean breakWhile = false; N E= w6
0x5xLg;Q
o.^y1mH'
while(!bStop) A]?^ H<
{ `o si"o9
write_nPos(); 8i:[:Z
Utility.sleep(500); |+NuYz?
breakWhile = true; K"l0w**Og#
&p"(-
3hS6jS
for(int i=0;i<nStartPos.length;i++) l h/&__
{ M<[?g5=#
if(!fileSplitterFetch.bDownOver) CgnXr/!L
{ %MJ;Q?KB
breakWhile = false; 8#59iQl
break; d+}kg
} Y {c5
} <xn;bp[
if(breakWhile) de YyaV
break; aws"3O% uW
Z;b+>2oL
A}G|Yfn
//count++; `|<+ ?
//if(count>4) Vk7=7%xW
// siteStop(); ~m`!;rE
} V8"Wpl9Cz
0YS?=oi
O3%[dR
System.err.println("文件下载结束！"); s#^pC*,'
} k/lFRi-i
catch(Exception e){e.printStackTrace ();} I]uhi{\C
} np6HUH
]}2Ztr)zZ
nY^Nbh0
//获得文件长度 d 4O
public long getFileSize() Fu)Th|5GZ
{ -&Gfh\_NW
int nFileLength = -1; hz)9"B\S
try{ ^ vbWRG~
URL url = new URL(siteInfoBean.getSSiteURL()); 2F?kjg,
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); n`L,]dco
httpConnection.setRequestProperty("User-Agent","NetFox"); h0VzIuV
nGrVw&
;nB2o-%
int responseCode=httpConnection.getResponseCode(); bPd-D-R
if(responseCode>=400) v8@eW.I1
{ @Fx@5e
processErrorCode(responseCode); FA$zZs10\
return -2; //-2 represent access is error EOVZGZF
} k dU! kj
@]'SeiNp
g%\L&}Jd
String sHeader; +?d}7zh
HDS"F.l5
\*"`L3
for(int i=1;;i++) xl] ;*&
{ =B(mIx;m
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); G6O/(8
//Utility.log(in.readLine()); 9L)L|4A.l
sHeader=httpConnection.getHeaderFieldKey(i); I/p]DT
if(sHeader!=null) ixw(c&gL
{ $TG?4
if(sHeader.equals("Content-Length")) .JAcPyK^
{ F2>%KuM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); d6.}.*7Whc
break; ?R6`qe_F
} 0BTLcEqgZ
} ,Y!zORv<7
else @ajM^L!O
break; OE"<!oIs
} ((MLM3zJ
} PXEKV0y
catch(IOException e){e.printStackTrace ();} xncwYOz
catch(Exception e){e.printStackTrace ();} ybvI?#
$qm~c[x%
FH\CK
Utility.log(nFileLength); cY{Nos
DO^y;y>
=A n`D
return nFileLength; NWKi ()nA%
} :ba/W&-d
C\Ayv)S#2
pm]fQuq
//保存下载信息（文件指针位置） @"8R3BN
private void write_nPos() ;<-7*}Dj
{ y/R+$h(%
try{ 0.DQO;
output = new DataOutputStream(new FileOutputStream(tmpFile)); K]"Kf{bx
output.writeInt(nStartPos.length); Tf-CEHWD
for(int i=0;i<nStartPos.length;i++) <abKiXA"
{ -p8e
// output.writeLong(nPos); ~A >oO-0K
output.writeLong(fileSplitterFetch.nStartPos); )H+kB<n
output.writeLong(fileSplitterFetch.nEndPos); dAxp ,):&J
} -g~~]K%
output.close(); %f!iHo+Z
} 7~vqf3ON4J
catch(IOException e){e.printStackTrace ();} <lo`q<q
catch(Exception e){e.printStackTrace ();} GqUSVQ
} )%mAZk-*;^
sh6(z?KP
=_QkH!vI
//读取保存的下载信息（文件指针位置） i6>R qP!69
private void read_nPos() 7/>a:02
{ A&N*F"q
try{ n,nisS
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Yx1 D)
int nCount = input.readInt(); RvW.@#EH0
nStartPos = new long[nCount]; aZgNPw
nEndPos = new long[nCount]; ?,% TU&Yn
for(int i=0;i<nStartPos.length;i++) 0Q1/n2V
{ 4}-#mBV]/
nStartPos = input.readLong(); \"d?=uFe
nEndPos = input.readLong(); \cZfg%PN
} 8p=>?wG
input.close(); afm_Rrg[
} f z%tA39m
catch(IOException e){e.printStackTrace ();} KXe ka
catch(Exception e){e.printStackTrace ();} E5{n?e
} O5-;I,)H
x!?Z*v@I
M 9"-WIG@h
private void processErrorCode(int nErrorCode) :]c=pH
{ F<r4CHfh;
System.err.println("Error Code : " + nErrorCode); ;r!\-]5$
} 0w3b~RJ
]{Ek[Av
xIgql}.
//停止文件下载 c]v +
public void siteStop() :6u~aT/
{ kF-TG3
bStop = true; :`J>bHE
for(int i=0;i<nStartPos.length;i++) ORH93`
fileSplitterFetch.splitterStop(); oT->^4WY
^saM$e^c:
Cef7+fa
} $l"MXxx5I
} vlQ0gsXK
//负责部分文件的抓取 x,1=D~L}
**FileSplitterFetch.java A&l7d0Z^j5
*/ RVP18ub.S
package NetFox; z!CD6W1n
-N z}DW>
|<Bpv{]P
import java.io.*; 7@P656{
import java.net.*; q6&67u0
-eL'KO5'
/f&By p
public class FileSplitterFetch extends Thread { k7T alR
;*QN9T=0
k1iLnza%
String sURL; //File URL ('d{t:TsY
long nStartPos; //File Snippet Start Position 1S*P"8N}0h
long nEndPos; //File Snippet End Position ~4^p}{
int nThreadID; //Thread's ID @1.9PR$x
boolean bDownOver = false; //Downing is over ]fC7%"nB
boolean bStop = false; //Stop identical ][t6VA
FileAccessI fileAccessI = null; //File Access interface $8@+j[>
W5I=X]&
\`gEu{
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException mJ$Htyr
{ CB]l[hM$
this.sURL = sURL; T*\$<-^
this.nStartPos = nStart; M=+M8M`Iy
this.nEndPos = nEnd; A^g>fv
nThreadID = id; hVZo"XUb
fileAccessI = new FileAccessI(sName,nStartPos);//定位 JUU&Z[6J
} ohplj`X[21
z8tl0gd%D
,'_(DJX
public void run() N 8}lt
{ b,Lw7MY}[
while(nStartPos < nEndPos && !bStop) kW(Kh0x
{ A'~#9@l<
kaO{#i2-
C8MWIX}
try{ jGiw96,Y
URL url = new URL(sURL); [R\=M'
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ?cxr%`E
httpConnection.setRequestProperty("User-Agent","NetFox"); 7@~QkTH~y
String sProperty = "bytes="+nStartPos+"-"; Y^3)!>
httpConnection.setRequestProperty("RANGE",sProperty); LP?P=c
Utility.log(sProperty); _H2tZ%RM
>Bx8IO1_\d
%^!aB
InputStream input = httpConnection.getInputStream(); H;wR
//logResponseHead(httpConnection); >{F!ntEj
b[0S=e G
R8uj3!3^
byte[] b = new byte[1024]; V4\560
int nRead; tQ[]Rc
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) G1p'p&x.
{ Um'Ro4
nStartPos += fileAccessI.write(b,0,nRead); :iEAUM
//if(nThreadID == 1) .FJj
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); raF] k0{
} QES^^PQe:
D&f!( n
LUG9 #.
Utility.log("Thread " + nThreadID + " is over!"); < GU
bDownOver = true; ^Rk^XQCh
//nPos = fileAccessI.write (b,0,nRead); !U[:5@s06
} ;L$,gn5H
catch(Exception e){e.printStackTrace ();} e3pnk =u
} }{t3SGsJ
} TR?Bvy2s:g
L,W:,i/C
?#i|>MRR>
//打印回应的头信息 v!KJ|c@m
public void logResponseHead(HttpURLConnection con) JeL~]F
{ ;da4\bppt
for(int i=1;;i++) py.!%vIOQ
{ Yu;9&b
String header=con.getHeaderFieldKey(i); ~Q0&P!k
if(header!=null) [lZ=s[n.
//responseHeaders.put(header,httpConnection.getHeaderField(header)); p_;r%o=
Utility.log(header+" : "+con.getHeaderField(header)); +dJ&tuL:S
else }q]jjs
break; k3#wLJ
} \D ^7Z97
} =~ '^;D
Z"]xdOre
JC/d:.
public void splitterStop() EFeAr@nj
{ \UhGGg%
bStop = true; R7,pukK
} UL[uh@4
z41D^}b
AT-0}9z{
} lqauk)(A0
8'n#O>V@
HMhLTl{;
/* !@A|L#*
**FileAccess.java ps"9;4P
*//文件访问(定位，写) Vl-D<M+ih
package NetFox; ;tm3B2
import java.io.*; zWJKYFqK
Ls(&HOK[p
u6f4yQ
public class FileAccessI implements Serializable{ v,8Si'"i+
kF#{An)P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 M*v^N]>"G
RandomAccessFile oSavedFile; y _6r/z^
long nPos; BL7>dZOa
'r6cVBb}
6RL~iD;X
public FileAccessI() throws IOException |I(%7K
{ X"wFQa
this("",0); vu44!c@
} UC.8DaIPN
]bf'
7bHE!#L`0
public FileAccessI(String sName,long nPos) throws IOException =%xIjxYl
{ ta@ISRK
oSavedFile = new RandomAccessFile(sName,"rw"); wQ@Zwbx
this.nPos = nPos; &:-GI)[o
oSavedFile.seek(nPos); C"(_mW{@
} I.UjST
C"k2<IE
~0av3G
public synchronized int write(byte[] b,int nStart,int nLen) BF>T*Z-Ki
{ 1xq3RD
int n = -1; av"Dljc
try{ F_K
oSavedFile.write(b,nStart,nLen); ?U=mcdqd
n = nLen; PKl]GegP
} MK<
catch(IOException e) 6^WiZ^~
{ iOKr9%9?Z
e.printStackTrace (); fi5YMYd1
} ux%&lff
^*HVP*
{`($Q$Q1
return n; QziN]
} jQO*oq}
hkkF1 h
}klE0<W|5\
} 7ZL,p:f
;OQ#@|D
,G/\@x%
/* 7YoofI
**SiteInfoBean.java 9yO{JgKA
*/ >hHJ:5y
package NetFox; Z83q-
SJso'6 g
#FrwfJOV
public class SiteInfoBean { Tnzco
:;|)/
xC= y^- 1
private String sSiteURL; //Site's URL F<6KaZ|
private String sFilePath; //Saved File's Path EGp~Vo-
private String sFileName; //Saved File's Name %i;r]z-
private int nSplitter; //Count of Splited Downloading File 9O(i+fM
XLkL#&Ir
MzBfHt'Rk
public SiteInfoBean() h;cB_6vt
{//nSplitter的缺省值为5 x@{G(W:W
//default value of nSplitter is 5 /vFxVBX
this("","","",5); z^gDbXS
} [lDt0l5^
d A_S"Zc
{hW +^
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) :F!dTD$
{ 9,Crmbw8
sSiteURL= sURL; .FfwY 'V
sFilePath = sPath; D=5t=4^H(
sFileName = sName; -s?dzX
this.nSplitter = nSpiltter; J4Q)`Y\~
)A>U<n$h
bc0)'a\
} mh!N^[=n
g:~?U*f-
?~]1Gd
public String getSSiteURL() .N-'; %8
{ nzQYn
return sSiteURL; u8{@PlS
} `Yo-5h
?<>,XyY
X:xC>4]gG'
public void setSSiteURL(String value) D7gX,e
{ cEh0Vh-]
sSiteURL = value; .,d$%lN
} H3UX{|[
`JY>v io
XNkQk0i;g&
public String getSFilePath() Cn6n4, 0
{ rw=UK`
return sFilePath; q>(I*=7
} 1?e>x91
~u~[E
s= GOB"G
public void setSFilePath(String value) V1CSXY\2
{ M<M#<kD
sFilePath = value; A .jp<>
} \gJapx(
Hb@G*L$
4$q)e<-
public String getSFileName() _x,-d|9bd
{ }]n>A
return sFileName; -Fok%iQ'5
} , $D&WH
`ykMh>*{
C-:SQf
public void setSFileName(String value) 1O'*X
{ *$4A|EA V
sFileName = value; k_En_\c?p2
} >H=Q$gI
%1 VNP(E
>zfZw"mEP
public int getNSplitter() [#P`_hx
{ =?`y(k4a
return nSplitter; Nak'g/uP>
} DO1N`7@o
^NnU gj
nY"rqILX?
public void setNSplitter(int nCount) c=jI.=mi3
{ ~Hyyq-
nSplitter = nCount; vhE}{ED
} p0y0T|H^
} m|e*Jc
G\,A> mT/P
bHWvKv+
/* #BT6bH08X
**Utility.java Fy(nu-W
*/ u_[4n
package NetFox; &\6`[# bT
} {gWTp
oZ*=7u
public class Utility { ffoo^1}1
4MF}FS2)
b/n8UxA
public Utility() n[MIa]dK
{ o,''f_tRQ|
$jm>tW&;
u{{xnyl?
} #iqhm,u7D
yOn2}Z
//线程睡眠 8NF;k5
public static void sleep(int nSecond) ttAVB{kdo
{ beHCEwh
try{ G(|(y=ck
Thread.sleep(nSecond); EkB6- nz
} `S/1U87
catch(Exception e) eM1;Nl
{ EB3o8
e.printStackTrace (); ]RrP !|^
} _G}CD|Kx
} }r<@o3t
\Q?|gfJH
//日志 M\.T 0M_
public static void log(String sMsg) [nPzhXs
{ FOUs= E[
System.err.println(sMsg); <*(UvOQuX
} oN6*WNtJ
g%q?2Nv
Qdx`c^4m
public static void log(int sMsg) X5oW[
{ X^_+%U
System.err.println(sMsg); UN .[,%<s
} 2Fp]S a
} d`],l\oC
{+UNjKQC
4pTuP /
/* _]~ht H
**TestMethod.java 84oW
*/ o|*|
package NetFox; m9<[bEO<$
WJh;p: q[
Ag-?6v
public class TestMethod { cmGj0YUQ1
ga1gd~a
M?4r5R
public TestMethod() j+B5m:ExfI
{ ///xx/weblogic60b2_win.exe 6quWO2x
try{ [TfV2j* e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 6_&6'Vq
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Q"K>ML>0
SiteFileFetch fileFetch = new SiteFileFetch(bean); [sY1|eX
fileFetch.start(); =*>4Gh i
} F6GZZKj
catch(Exception e){e.printStackTrace ();} 1PTu3o&3
~ GT\RAj[
QVRokI`BF
} Gv+Tg/
?VN]0{JSp
(#l_YI -
public static void main(String[] args) G$kwc F'C
{ NUNn[c
new TestMethod(); UE#Ni 5
} aaD$'Y,<>B
} JQh s=Xg
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