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)); 7MKD_`g
} <'r0r/0g?
for(int i=0;i<nEndPos.length-1;i++) Iv'RLM
{ +:Lk^Ny
nEndPos = nStartPos[i+1]; NzjMk4t
} ?cqicN.+6
nEndPos[nEndPos.length-1] = nFileLength; gJ]Cq/gC
} PYdIP\<V
} 5."5IjZu
U8 Z~Y}29
' oBo|
//启动子线程 gb.f%rlZ`
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Q{H17]W
for(int i=0;i<nStartPos.length;i++) TFBYY{Y
{ T&?w"T2y
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), hmc\|IF`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 1Z\(:ab13
nStartPos,nEndPos,i); 5gO/-Zj
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); }BA9Ka#%
fileSplitterFetch.start(); ]b}B~jD
} Bs_S.JP<`
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), KjO-0VMN3
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); gsnP!2cR
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", BmJkt3j."
nEndPos = " + nFileLength); x}v1X`6b
// fileSplitterFetch[nPos.length-1].start(); MinbE13?U
J2rvJ2l=t
`2>XH:+7F
//等待子线程结束 smQ4CLJ
//int count = 0; >NJjS8f5
//是否结束while循环 $kD7y5
boolean breakWhile = false; EY So=
BTOA &Ag
^&C&~}Zv
while(!bStop) uK"^*NEC';
{ 3.(.*>
write_nPos(); Hr(6TLNw
Utility.sleep(500); xcHen/4X
breakWhile = true; D0f*eSXE{
)X7e$<SU*
:M@MmpPh
for(int i=0;i<nStartPos.length;i++) a@Mq J=<L
{ B,4q>KQA
if(!fileSplitterFetch.bDownOver) (RExV?:
{ Kl2}o|b
breakWhile = false; L{!ihJr
break; :lNg:r$4
} D)y{{g*Lnm
} PXa5g5!
if(breakWhile) [w,(EE
break; +yGY785b
h5x*NM1Ih
{W-5:~?"
//count++; M|ms$1x
//if(count>4) !IN@i:m
// siteStop(); -<xyC8$^$
} :MK=h;5Z
B#1:Y;Z
mU>&ql?e
System.err.println("文件下载结束！"); `(3SfQ-
} <]~ZPk[
catch(Exception e){e.printStackTrace ();} h(_P9E[g
} \WcB9
[ne" T
4b]_ #7Qm
//获得文件长度 2%5?Fn=
public long getFileSize() `N$!s7M
{ <3lUV7!
int nFileLength = -1; l"kxr96
try{ `-o5&>'nf
URL url = new URL(siteInfoBean.getSSiteURL()); {>/)5AGs
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); F,Q?s9s
httpConnection.setRequestProperty("User-Agent","NetFox"); R'L?Xn}3
{H+?z<BF<
bQ<b[
int responseCode=httpConnection.getResponseCode(); 3&$Nd
if(responseCode>=400) k5wi'
{ !5&%\NSv
processErrorCode(responseCode); i=-8@
return -2; //-2 represent access is error eI0F!Yon
} MO-!TZ+6
w(Gz({l+
kymn)Ea
String sHeader; '[Xl>Z[
#K|0laul
\04mLIJr9
for(int i=1;;i++) |gW
{ 3524m#4&@
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); Qo.Uqz.C
//Utility.log(in.readLine()); alc]
sHeader=httpConnection.getHeaderFieldKey(i); DKTD Z*
if(sHeader!=null) "?P[9x}
{ L@nebT;\'
if(sHeader.equals("Content-Length")) F;pQ\Y
{ zFywC-my@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); !9DX=?
break; jQ?LHUE
} #sZIDn J#
} %&tb9_T)d
else .1LPlZ
break; gJh}CrU-
} 2 Kla8
} Sl"BK0:%7
catch(IOException e){e.printStackTrace ();} K^aj@2K{
catch(Exception e){e.printStackTrace ();} }"n7~|
qi&D+~Gv!
U;pe:
Utility.log(nFileLength); 1M+oTIN
R]Ek}1~?
IM=+3W;ak
return nFileLength; ei|cD[ NY
} \DS^i`o)rY
@;;G88=
)&,K94
//保存下载信息（文件指针位置） };r|}v !~_
private void write_nPos() 1A^1@^{m'
{ (N0sE"_~I5
try{ O:e#!C8^
output = new DataOutputStream(new FileOutputStream(tmpFile)); @o&Ytd;i
output.writeInt(nStartPos.length); ?Wa<AFXQ
for(int i=0;i<nStartPos.length;i++) [Tp%"f1
{ nv)))I\
// output.writeLong(nPos); w.uK?A>W,
output.writeLong(fileSplitterFetch.nStartPos); !R6ApB4ZI
output.writeLong(fileSplitterFetch.nEndPos); (ii(yz|
} ,#d[ad<
output.close(); `eC+% O
} ;Xu22fKh
catch(IOException e){e.printStackTrace ();} ?}8IQxU
catch(Exception e){e.printStackTrace ();} B?3juyB`--
} hVM2/j
Xu#:Fe}:
Xpl?g=B&u
//读取保存的下载信息（文件指针位置） 88l,&2q
private void read_nPos() nP1GW6Pu
{ 8_a3'o%5
try{ !y. $J<
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); \I:.<2i
int nCount = input.readInt(); aMJ;bQD
nStartPos = new long[nCount]; {cR=N~_EO
nEndPos = new long[nCount]; Rh<N);Sl7
for(int i=0;i<nStartPos.length;i++) DsGI/c
{ %i"}x/CD[
nStartPos = input.readLong(); 5un^yRMB-
nEndPos = input.readLong(); g<a<*)&
} ^N-'xy
input.close(); #\ #3r
} b#a@rh
catch(IOException e){e.printStackTrace ();} ,r`UBQ}?
catch(Exception e){e.printStackTrace ();} :gf;}
} NXI[q'y
uR_F,Mp?%u
uPLErO9Es[
private void processErrorCode(int nErrorCode) m$:&P|!'p
{ X#ZgS!Mn
System.err.println("Error Code : " + nErrorCode); 5)M2r!\
} {/|qjkT&W
eFFc9'o
v{y{sA
//停止文件下载 J(s;$PG
public void siteStop() {G*OR,HN
{ h1f8ktF
bStop = true; j?-R]^-5
for(int i=0;i<nStartPos.length;i++) 7&+Ys
fileSplitterFetch.splitterStop(); FN?3XNp.
`R+,1"5=
[@G`Afaf
} aWGon]2p
} Mu2`ODe]
//负责部分文件的抓取 OCK>%o$[
**FileSplitterFetch.java BQ#L+9%
*/ m@\ZHbq
package NetFox; @Y-TOCadT
0^&!6R
Cj^{9'0
import java.io.*; x8"#!Pw:`"
import java.net.*; >qh?L#Fk
]tY:,Mfs
Cv^`&\[SW+
public class FileSplitterFetch extends Thread { ;`UecLb#
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tsv$r$Se
String sURL; //File URL Lgi[u"Du
long nStartPos; //File Snippet Start Position ]db@RbaH
long nEndPos; //File Snippet End Position kg>>D
int nThreadID; //Thread's ID K5k?H
boolean bDownOver = false; //Downing is over h{_*oBa
boolean bStop = false; //Stop identical %e_"CS
FileAccessI fileAccessI = null; //File Access interface H l<$a"K7\
X3B{8qx_>
:2y"3azxk
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException "HlgRp]u
{ zwr\:Hu4
this.sURL = sURL; "b,%8
this.nStartPos = nStart; 1@_T m
this.nEndPos = nEnd; #/ "+
nThreadID = id; Z cpmquf8L
fileAccessI = new FileAccessI(sName,nStartPos);//定位 /3B6Mtb
} _0(7GE13p
b{5K2k&,
-JV~[-,
public void run() p]ivf
{ HOZRYIQB
while(nStartPos < nEndPos && !bStop) OYmi?y\
{ 8)wt$b
hfrnxeM#~
C@gXT]Q 0}
try{ +sZUJ
URL url = new URL(sURL); =yXs?y"
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L CSeOR
httpConnection.setRequestProperty("User-Agent","NetFox"); YnTB&GPxl
String sProperty = "bytes="+nStartPos+"-"; }roG(
httpConnection.setRequestProperty("RANGE",sProperty); AK-}V4C/A
Utility.log(sProperty); 2Z/K(J"&J
KnzsHli,~k
JTW)*q9a
InputStream input = httpConnection.getInputStream(); Q6'nSBi:A_
//logResponseHead(httpConnection); L*JPe"N-e
~cqryr9
P Sx304
byte[] b = new byte[1024]; z`U Ukl}T
int nRead; c`G&KCw)d
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ;3m!:l
{ i8PuC^]
nStartPos += fileAccessI.write(b,0,nRead); Qa`hR
//if(nThreadID == 1) ^b-18 ~s
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); tIuoD+AW
} nII^mg~
%y<]Yzv.
jirbUl
Utility.log("Thread " + nThreadID + " is over!"); $_X|,v9
bDownOver = true; 23ze/;6%A
//nPos = fileAccessI.write (b,0,nRead); i7Z=|&
} ]axh*J3`i
catch(Exception e){e.printStackTrace ();} *xs!5|n+
} ~?Omy8#
} <J{'o`{
I+;-p]~
Tg ?x3?kw
//打印回应的头信息 f CcD&<%
public void logResponseHead(HttpURLConnection con) aT!;{+
{ "!UVs+)]
for(int i=1;;i++) P?ep]
{ 3,eIB(
String header=con.getHeaderFieldKey(i); ma& To=
if(header!=null) "Ty/k8?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); KfY$ka[}"S
Utility.log(header+" : "+con.getHeaderField(header)); ,,<PVTd
else uCP>y6I
break; rrBAQY|.
} HOi C
} E]} n(
.dmi#%W
l!~ mxUb
public void splitterStop() BavO\{J#|0
{ SpSnoVI
bStop = true; b=[?b+
} z1V#'$_5-
6Y384
6oL1_)
} Mi7y&~,
(ywo a
*cv}*D
/* !1sU>Xb4J
**FileAccess.java .ln8|;%
*//文件访问(定位，写) Iy7pt~DJ,
package NetFox; ;/8{N0
import java.io.*; [=TCEU{"~
SU%DW46
uB.-t^@
public class FileAccessI implements Serializable{ >_ \<E!j
LMl~yqM
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 9.+/~$Ht
RandomAccessFile oSavedFile; ,LYFEq_
long nPos; (9RslvKL
?Dsm~bkX[
n(;:*<Rh
public FileAccessI() throws IOException mY&ud>,U:
{ =(, ^du'
this("",0); N2,D:m\
} xFFr
mZvG|P$}
b"j|Bb
public FileAccessI(String sName,long nPos) throws IOException yJJ4~j){l
{ EeQ5vqU
oSavedFile = new RandomAccessFile(sName,"rw"); w~\%vXla
this.nPos = nPos; JBX[bx52<r
oSavedFile.seek(nPos); dZ(|uC!?
} 4dh+
Ca>&
vK'?:}~
public synchronized int write(byte[] b,int nStart,int nLen) ]<w:V`(
{ 5\4g>5PD
int n = -1; =hH.zrI6e
try{ 5z/Er".P
oSavedFile.write(b,nStart,nLen); )mN9(Ob!
n = nLen; 2XSHZ|;
} e$/B_o7(
catch(IOException e) u\e\'\
{ zA+@FR?
e.printStackTrace (); 2%UBwSiqR
} i u]&;
tpf7_YP_!-
6vy7l(%
return n; z01>'
} (!K_Fy@
tbDoP Y
E+xuWdp.*
} pw020}`
i^"+5Eq[D
$p* p
/* =[tSd)D,y
**SiteInfoBean.java 2 h|e
*/ HeN~c<NuB
package NetFox; d5j_6X
'3(l-nPiG^
\ZXLX'-
public class SiteInfoBean { 7*H:Ob)9k
x8#ODuH
SAv<&
private String sSiteURL; //Site's URL `k{& /]
private String sFilePath; //Saved File's Path \c`oy=qY0
private String sFileName; //Saved File's Name Es5p}uh.[Y
private int nSplitter; //Count of Splited Downloading File 8\ha@&p
QBJ3iQs1
j6}R7$JR
public SiteInfoBean() _%@=Uc6V
{//nSplitter的缺省值为5 \' li
//default value of nSplitter is 5 RMYP"
this("","","",5); n-;y*kD
} =bt]JRU
>`T5]_a
]dPZ.r
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) p='-\M74K
{ deX5yrvOie
sSiteURL= sURL; )h$NS2B`
sFilePath = sPath; Vd9@Dy
sFileName = sName; (&\aA 0-}H
this.nSplitter = nSpiltter; \k8rxW
keAcKhj
}E^S]hdvz
} X=X\F@V:u
B0UJq./`
ZXb0Y2AVx
public String getSSiteURL() wdE?SDs
{ %'Xk)-+y
return sSiteURL; &~DTZgY
} k!XhFWb
[THG4582oB
B7*}c]^6/
public void setSSiteURL(String value) Z0,~V
{ tx7~SUr
sSiteURL = value; vq'c@yw;
} UH`hOJ?
?:rx1}:F
QP I+y8N=
public String getSFilePath() :Og:v#r8=
{ ?>uew^$d[w
return sFilePath; SpTdj^]4>
} p#d+>7
kUHE\L.Y]
/FY2vDfU6
public void setSFilePath(String value) KU&G;ni2
{ ,2[ra9n
sFilePath = value; ?[)S7\rP
} r8MZvm2
/i|z.nNO
d4^`}6@
public String getSFileName() Tp%(I"H'_;
{ pa .K-e)Mu
return sFileName; 3eIr{xs
} nY?
}k$4/7ri
wOgE|n
public void setSFileName(String value) S4NL "m
{ eo]#sf@\0
sFileName = value; 0Ce]V,i6C>
} zzpZ19"`1
rx~[Zs+*
AD5) .}[F
public int getNSplitter() !%L,*'
{ &Y>zT9]$K
return nSplitter; 9|r* pK[
} ,%"xH4d
h+UnZfm
,8Iv9M}2
public void setNSplitter(int nCount) m 40m<@
{ 6)RbPPeE
nSplitter = nCount; >O9sk
} EYS>0Y
} ]L_w$ev'
pR os{Uq"
`|e!Kq?#Q
/* IfdI|ya
**Utility.java H. ,;-
*/ h=VqxGC&
package NetFox; dXvt6kF
4)-)#`K
nY-* i!H
public class Utility { aC=['a>)
~Vh=5J~
my\&hCE
public Utility() Iq5pAHm>M6
{ b}z`BRCc
.#6MQJ]OH
RNJFSD.
} Va<HU:<
jRZ%}KX
//线程睡眠 0NE{8O0;Fr
public static void sleep(int nSecond) ~9o6 W",
{ lPq\=V
try{ oY9FK{
Thread.sleep(nSecond); U..<iNQE5
} [IX+M#mf
catch(Exception e) V-W'RunnW
{ =jAFgwP\
e.printStackTrace (); nL`9l1
} 0~A#>R'
} eb:A1f4L
<>&=n+i
//日志 {eZ{]
public static void log(String sMsg) t1]6(@mj5
{ qk{'!Ii
System.err.println(sMsg); <lwuTow
} %IZ)3x3l
l[h'6+o
.-I|DVHe
public static void log(int sMsg) pK_?}~
{ 9(1rh9`=
System.err.println(sMsg); #*$p-I=
} !rL<5L
} kEN#u
%CH6lY=lI
$^%N U
/* 0%C^8%(x
**TestMethod.java C0C0GqN,
*/ H'g?llh1J
package NetFox; 4cgIEw[6
S>:,z}i
=]>%t]
public class TestMethod { 4*H"Z(HP
>%%=0!,yX
-$k>F#
public TestMethod() xF8S*,#,*
{ ///xx/weblogic60b2_win.exe I}0_nge
try{ J1F{v)T'?
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); NP t(MFK\
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); dSK0h(8
SiteFileFetch fileFetch = new SiteFileFetch(bean); u=K2Q4
fileFetch.start(); ~UMOT!4}3
} t8J/\f=
catch(Exception e){e.printStackTrace ();} RVM&4#E
S3\jcgrS
E,"&-`/2v
} JSVeU54T^<
^$?qT60%d|
APBK9ky
public static void main(String[] args) :h5J r8
{ MgJ5B(c
new TestMethod(); ]#eh&jw
} [/9(NUf
} 8e:vWgQpL
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