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)); vf^`'
} xO3-I@
for(int i=0;i<nEndPos.length-1;i++) f_'#wc6
{ $^~dqmE2,
nEndPos = nStartPos[i+1]; _!_%Afz
} apmZ&Ab
nEndPos[nEndPos.length-1] = nFileLength; +9yV'd>U
} v@n0ma=
} d>k)aIYp
!'#Y-"=ypk
[ 'aSPA
//启动子线程 o>~xrV`E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; m}`!FaB #
for(int i=0;i<nStartPos.length;i++) nz+k ,
{ nymro[@O~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), N#C,q&;
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), 'qoDFR\v
nStartPos,nEndPos,i); 4+?d0
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 8p"R4
fileSplitterFetch.start(); @?bO@
} s&.VU|=VQ@
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), a\_?zi]s&,
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); *UxN~?N|
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", E)ne z
nEndPos = " + nFileLength); N./l\NtZ
// fileSplitterFetch[nPos.length-1].start(); :^bjn3b
a]NH >d
Ga,+
//等待子线程结束 2d:IYCl4q
//int count = 0; V d`}F0WD
//是否结束while循环 J2Y S+%K
boolean breakWhile = false; 4rDaJd>,
ku*H*o~
'j&+Pg)@
while(!bStop) ^(79SOZC
{ V)q|U6R
write_nPos(); ip)gI&kN`z
Utility.sleep(500); D^dos`L0b
breakWhile = true; #cGn5c}
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g._`"c
for(int i=0;i<nStartPos.length;i++) &[#iM0;)W0
{ lD+f{GR
if(!fileSplitterFetch.bDownOver) ]'q"Kw/10
{ Fm-D>PR
breakWhile = false; p#A{.6Pa:
break; OUM^u*
} MqKf'6z
} D2N<a=#
if(breakWhile) 'cgB$:T}.,
break; YZ\a#s,0
4;;K1< 1
P[q 'Y^\
//count++; N$I@]PL
//if(count>4) BK*Bw,KQ<
// siteStop(); .G/>X%X
} VV'*3/I
vr2cDk{
mu$0x)
System.err.println("文件下载结束！"); =]F;{x
} D:Rr|m0Tk
catch(Exception e){e.printStackTrace ();} Z)qts=
} 9jkaEn>m^
=sFLzAu8
1ZZ}ojq
//获得文件长度 f5tkv<) %
public long getFileSize() F4X0DRC,G
{ _DD.#YB</
int nFileLength = -1; G?$0OU
try{ p3`odmbN
URL url = new URL(siteInfoBean.getSSiteURL()); wbImE;-Z
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); $v \@mW*R
httpConnection.setRequestProperty("User-Agent","NetFox"); D}i_#-^MH
P;' xa^Y
rfH'&k
int responseCode=httpConnection.getResponseCode(); .e Jt]K
if(responseCode>=400) #)BbW40f6
{ 5`tMHgQO
processErrorCode(responseCode); /\-iV)h1@
return -2; //-2 represent access is error ] -}Zd\Rs
} W|,Y*l
I 7 B$X=
XLq%nVBM8\
String sHeader; Ec4+wRWk85
P/?'ea
c|hT\1XR,
for(int i=1;;i++) rY:A LA
{ Et0[HotO
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); 4z*An}ol]
//Utility.log(in.readLine()); \ )'`F; P
sHeader=httpConnection.getHeaderFieldKey(i); #]vs*Sz
if(sHeader!=null) Ex`!C]sQ
{ 3v?R"2\qS
if(sHeader.equals("Content-Length")) aePLP
{ Oye:V
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); TQ`4dVaf
break; `=QRC.b
} k.@OFkX.
} {9_}i#,vR
else K.l7yBm
break; 552yzn1
} }]BH "
} _&U.DMt2 C
catch(IOException e){e.printStackTrace ();} ~jOn)jBRZ
catch(Exception e){e.printStackTrace ();} OA?pBA
2leTEs5aK`
kKlcK_b;
Utility.log(nFileLength); *= ;M',nx
_X/`7!f
p*ic@n*G
return nFileLength; rAwuWM@BIg
} :GBM`f@
m]"13E0*x
}j\_XaB
//保存下载信息（文件指针位置） y} W-OLE
private void write_nPos() jwQ(E
{ sc)}r_|g
try{ E(p*B8d
output = new DataOutputStream(new FileOutputStream(tmpFile)); qh)10*FB
output.writeInt(nStartPos.length); sk>E(Myo
for(int i=0;i<nStartPos.length;i++) +[_mSt
{ PgMU|O7To
// output.writeLong(nPos); sCrOdJ6|
output.writeLong(fileSplitterFetch.nStartPos); yzH[~O7
output.writeLong(fileSplitterFetch.nEndPos); 8x/]H(J
} "> ]{t[Ib
output.close(); xC}9W6
} l.3|0lopX)
catch(IOException e){e.printStackTrace ();} IMT]!j&Y,
catch(Exception e){e.printStackTrace ();} qW"
} JIH6!
L!l`2[F|
lk/[xQ/
//读取保存的下载信息（文件指针位置） B3NDx+%m
private void read_nPos() #fQ}8UxU,
{ [5T{`&
try{ MUjfqxTT
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); F15Yn
int nCount = input.readInt(); &4}Uaxt)
nStartPos = new long[nCount]; *kM^l!<g
nEndPos = new long[nCount]; <>?7veN92
for(int i=0;i<nStartPos.length;i++) |%~Zo:Q<$>
{ l'm\*=3
nStartPos = input.readLong(); Z^_-LX:%
nEndPos = input.readLong(); *k^'xL
} T P#Hq
input.close(); q1_iV.G<
} WH^^.^(i
catch(IOException e){e.printStackTrace ();} +>Xe_
catch(Exception e){e.printStackTrace ();} 2^f6@;=M
} *{fL t
JK=0juv<E
)wdTs>W7
private void processErrorCode(int nErrorCode) 79MF;>=tV
{ Gw@]w;ed
System.err.println("Error Code : " + nErrorCode); -:~"c@D
} MIx,#]C&
ziXZJ^(FI
Y)*:'&~2e
//停止文件下载 X Z4q{^o
public void siteStop() -?}Z0e(w
{ &cuDGo.
bStop = true; 3-6Lbe9H
for(int i=0;i<nStartPos.length;i++) XFmTr@\M
fileSplitterFetch.splitterStop(); 40$- ]i
vp2s)W8W
~|kSQ7O^
} gT0N\oU"
} EZb_8<DH
//负责部分文件的抓取 efUa[XO
**FileSplitterFetch.java {,Z-GJ
*/ @{LD_>R
package NetFox; NR9=V
l)K8.(2
O+ghw1/
import java.io.*; <4%cKW0
import java.net.*; ;,7/>Vt
K|V<e[X[V
+DwE~l
public class FileSplitterFetch extends Thread { OGWZq(c"6
x3tos!Y
{[:]}m(c
String sURL; //File URL J2avt
long nStartPos; //File Snippet Start Position rZ:-%#Q4
long nEndPos; //File Snippet End Position 8kYI ~
int nThreadID; //Thread's ID u [Dz~
boolean bDownOver = false; //Downing is over >HL$=J_K?
boolean bStop = false; //Stop identical @CNe)&U
FileAccessI fileAccessI = null; //File Access interface 8m"(T-wb6{
{\p&?
;&OVV+y
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ttfCiP$
{ Pk/3oF
this.sURL = sURL; ]}z"H@k
this.nStartPos = nStart; ,9YgznQ
this.nEndPos = nEnd; &qMt07
nThreadID = id; `JzP V/6
fileAccessI = new FileAccessI(sName,nStartPos);//定位 >j6"\1E+Dz
} #dhce0m
y*7{S{9
7 <<`9,
public void run() g|=1U
{ }-N4D"d4o
while(nStartPos < nEndPos && !bStop) F|bg2)|du8
{ .g?Ppma
~v|NC([(
kkU#0p?7
try{ kA4bv}
URL url = new URL(sURL); r(OH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); .8]buM5_G
httpConnection.setRequestProperty("User-Agent","NetFox"); ./@C
String sProperty = "bytes="+nStartPos+"-"; YMr2Dv\y
httpConnection.setRequestProperty("RANGE",sProperty); 7w5C NV
Utility.log(sProperty); ';zS0Yk
PFI^+';
%@MO5#)NI
InputStream input = httpConnection.getInputStream(); Lu5lpeSQ
//logResponseHead(httpConnection); /H~]5JZ3-E
}F4%5go
2e^6Od!Y?
byte[] b = new byte[1024]; 0@>
int nRead; GAU7w"sE
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) (MzThGJK_
{ EV[ BB;eb
nStartPos += fileAccessI.write(b,0,nRead); %v)+]Ds{
//if(nThreadID == 1) {&uN q^Ch
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); Vu5Djx'
} F#KUu3;B
WGA"e
p>h}k_s
Utility.log("Thread " + nThreadID + " is over!"); #&,~5
bDownOver = true; [pX cKN
//nPos = fileAccessI.write (b,0,nRead); Vi<6i0
} ,u S)N6'b6
catch(Exception e){e.printStackTrace ();} THy{r_dx
} AYsiaSTRqW
} ,Q,3^v-
e!N%
'b:UafV
//打印回应的头信息 UFGUP]J>
public void logResponseHead(HttpURLConnection con) _jM+;=f
{ /RemLJP F
for(int i=1;;i++) ^KUM4. 6
{ &xE+PfX
String header=con.getHeaderFieldKey(i); s8+{##"1 q
if(header!=null) EYR%u'&7'
//responseHeaders.put(header,httpConnection.getHeaderField(header)); bltZQI|
Utility.log(header+" : "+con.getHeaderField(header)); 9S/X,|i
else x\b+B
break; ;T3}#Q*qC
} aE[:9{<|
} kJ"}JRA<
![ @i+hl
Y/]J0D
public void splitterStop() $E-c%-
{ [B@R(z=H
bStop = true; L*zfZ&
} 8d[!"lL
Cig!3
S9{&.[O
} 2[I[I*"_d
KvmXRf*z
HE@P<
/* U"OA m}
**FileAccess.java i?n#ge
*//文件访问(定位，写) <(_${zR
package NetFox; Gdv{SCV
import java.io.*; QRHM#v S
!laOiH
plgiQr #
public class FileAccessI implements Serializable{ 7VW/v4n
IPk"{T3
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 \4Z"s[8}
RandomAccessFile oSavedFile; EfqC_,J*3
long nPos; C^ZDUj`
&uXu$)IZ
N4w&g-
public FileAccessI() throws IOException Dpkc9~z
{ +?^lnoX
this("",0); 6.6x$y3v
} yX1OJg[s,
<4Ik]Uz^
u"-."_
public FileAccessI(String sName,long nPos) throws IOException ,B$e'KQ
{ 1i}p?sU
oSavedFile = new RandomAccessFile(sName,"rw"); pykRi#[UrX
this.nPos = nPos; nmoC(| r
oSavedFile.seek(nPos); t'*2)U
} q(Zu;ecBN
S#l)|c_~
-~_;9[uV
public synchronized int write(byte[] b,int nStart,int nLen) $: qrh66
{ O4T_p=Xc
int n = -1; N:UA+
try{ ;fB!/u
oSavedFile.write(b,nStart,nLen); w"AO~LF
n = nLen; v<E_n;@9k
} ZmZ7E]c
catch(IOException e) r?}L^bK
{ -z'6.IcO
e.printStackTrace (); # N'_~:H
} =' &TqiIv"
l-M .C8N
<^"0A
return n; r-ljT<f%J[
} VE*&t>I
^K[[:7Aem
4_w{~
} |VmQ
Vc&xXtm[v
D`NQEt"(
/* :PP!v!vk
**SiteInfoBean.java ~i=5NUE
*/ X@Yl<9|i
package NetFox; lQ|i Ws
)P9&I.a8
~}ba2dU8
public class SiteInfoBean { g&d tOjM
2qPQ3-'
p/Ri|FD6
private String sSiteURL; //Site's URL M~-jPY,+
private String sFilePath; //Saved File's Path M(.Up
private String sFileName; //Saved File's Name C[nacAi
private int nSplitter; //Count of Splited Downloading File T9]:, z
jo ~p#l.'
A~#w gLGn
public SiteInfoBean() -}P/<cu:
{//nSplitter的缺省值为5 dgW/5g
//default value of nSplitter is 5 kx07Ium
this("","","",5); #RP7?yGM,
} L%fJH_$_s
i~.9B7hdE
XZ_vbYTj
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) =QW:},sp
{ e'&<DE)
sSiteURL= sURL; Pql;5 ~/
sFilePath = sPath; RaAvPIJa |
sFileName = sName; 8~vE
this.nSplitter = nSpiltter; UE K$
v v]rXJu1
V,>uM >$
} ItwJL`
)k&!&
B/bS:
public String getSSiteURL() z+X DN:
{ ~jM!8]=
return sSiteURL; e18}`<tW-
} !f*t9 I9Q
Cm[^+.=I
sU;aA0kz
public void setSSiteURL(String value) qm|T<zsDY#
{ pR7D3Q:^7
sSiteURL = value; d1n*wVl
} <amdPo+2D
t"FB}%G
'L ]k\GO
public String getSFilePath() H05U{vR
{ K6e_RzP,.w
return sFilePath; mW_ N-z
} ;09U*S$eK
gIcm`5+T
gBJM|"_A?
public void setSFilePath(String value) K)TMr"j\
{ NEcE-7aT
sFilePath = value; zn/b\X/
} Q5/BEUkC
gshgl3
b[ .pD3
public String getSFileName() 8B|B[,`
{ [:bYd}J
return sFileName; mE3M$2}
} ec"+Il
p|VgtQ/)%
4'U #<8
public void setSFileName(String value) p$zj2W+sN
{ S'%!KGVe
sFileName = value; R^tDL
} VT5o#NR{R
uI+^8-HZ;
IjnO2X
public int getNSplitter() (xlAS
{ F!~oJ
return nSplitter; QOKE9R#Y
} _.K<#S
i2m+s;
xGo,x+U*
public void setNSplitter(int nCount) {igVuZ(>en
{ Evb %<`gd
nSplitter = nCount; ewp&QH4
} Nt P=m @
} FOD_m&+
?;?$\b=
z.]
/* V]0~BV
**Utility.java 2^T`> ?{X
*/ \EOPlyf8x
package NetFox; U+'h~P'4
e$=0.GWT
sboX<
public class Utility { %TA@-tK=
`=VN\W^&
&/tGT3)
public Utility() 6qkMB|@Ix
{ DXc3u^ L
dMjAG7U
qo62!q
} :/941?%M
E6mwvrm8
//线程睡眠 J:JkX>n%k=
public static void sleep(int nSecond) "I)`gy&
{ MPF;P&6
try{ zd^QG
Thread.sleep(nSecond); .m_-L Y-
} |)IS[:X
catch(Exception e) [SX>b"L
{ Hv.nO-c
e.printStackTrace (); ecG,[1];
} 9|9Hk1
} {8Uk]
kPg| o3H
//日志 s'^"s_j
public static void log(String sMsg) Y76UhtYH
{ '}.Z' %;
System.err.println(sMsg); !pG_MO
} xcA5
xix:= a
]Y@B= 5e/
public static void log(int sMsg) n*vzp?+Y
{ Ht!]%
System.err.println(sMsg); S1oP_A[|
} Qfd4")zhG
} 13KfI
uf<nVdC.
N)b.$aC
/* 2#?qey
**TestMethod.java |ZuS"'3_w
*/ ^i!6q9<{e
package NetFox; "~^#{q
-=CZhp
O0Sk?uJ<
public class TestMethod { ^P !}"
/R% Xkb
u?+i5=N9{
public TestMethod() 5$.e5y<&(
{ ///xx/weblogic60b2_win.exe i$:QOMA
try{ M h5>@-fEE
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); A9L {c!|-
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); F;;\I
SiteFileFetch fileFetch = new SiteFileFetch(bean); %an&lcoX
fileFetch.start(); N% W298
} Uc<j{U ,
catch(Exception e){e.printStackTrace ();} S eTn]
"[t (u/e
qH1&tW$
} E+xC1U 3
HbXYinG%
p&|:,|jo5
public static void main(String[] args) ytg' {)
{ c mI&R(
new TestMethod(); uF89B-t
} 236,o {9e
} TowRY=#jiS
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