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)); 2RC@Fu~zaU
} Kzf^ras4u
for(int i=0;i<nEndPos.length-1;i++) j`ybzG^
{ bx=9XZ9g
nEndPos = nStartPos[i+1]; dEG1[QG
} D./3,z
nEndPos[nEndPos.length-1] = nFileLength; mM)d`br
} DS6g_SS3
} R\,qL-Br
o`}(1$a>
ZRLS3*`
//启动子线程 8/`ij?gn
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; mZ}C)&,m2
for(int i=0;i<nStartPos.length;i++) ~k780
{ pQ yH`
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), njg\y
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), &1$|KbmV4
nStartPos,nEndPos,i); fVx_]5jM
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); XD$;K$_7
fileSplitterFetch.start(); UJhUb)}^
} JWo).
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), U((mOm6
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); [3fmhc
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", LQ3J$N
nEndPos = " + nFileLength); o`<ps$yT
// fileSplitterFetch[nPos.length-1].start(); D/]
)G=hgqy
Ki(
//等待子线程结束 HA0Rv#p
//int count = 0; gtlyQ _V
//是否结束while循环 VAet!H+]
boolean breakWhile = false; vfPIC!
]iE)8X
@'fWS^ ;&
while(!bStop) \:|"qk
{ KW-g $Ma
write_nPos(); 2V)qnMxAZJ
Utility.sleep(500); `=JGlN7
breakWhile = true; !@wG22iC4d
Bl!R bh\
u RPvo}!=1
for(int i=0;i<nStartPos.length;i++) XVWVY}
{ -G@:uxB
if(!fileSplitterFetch.bDownOver) B[B(=4EzMP
{ d gRTV<vM
breakWhile = false; I4\ c+f9
break; YqNI:znm-
} _ !H8j/b
} 3}25=%;[
if(breakWhile) fZF.eRP'
break; 8PtX@s43\
>a$b4 pvh
p4M7BK:nf
//count++; I^itlQ
//if(count>4) WuUT>omH
// siteStop(); C3GI?|b
} 3JcI}w
?Y|*EH
A!.* eIV|
System.err.println("文件下载结束！"); VaLl$w
} <Z^qBM
catch(Exception e){e.printStackTrace ();} SlojB^%
} V07? sc<
)*I%rN8b
]n$&|@
//获得文件长度 k}$k6Sr"
public long getFileSize() n9x&Ws;
{ bdz&"\$X
int nFileLength = -1; gt{$G|bi
try{ |cd=7[B
URL url = new URL(siteInfoBean.getSSiteURL()); @!:_r5R~N
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); KM jnY2
httpConnection.setRequestProperty("User-Agent","NetFox"); bk{.9nz2
%2t#>}If!
H]d'#1G
int responseCode=httpConnection.getResponseCode(); oq3{q
if(responseCode>=400) ~sUWXw7~
{ 9HJA:k*k|
processErrorCode(responseCode); Z5%TpAu[
return -2; //-2 represent access is error _rjLCvv-
} 2-!n+#Cdf
1?5UVv_F
jFThW N
String sHeader; xFy%&SKHg
lM'yj}:~
/'g"Ys?3
for(int i=1;;i++) $,L,VYN
{ {%Ujp9i
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dgsD~.((A
//Utility.log(in.readLine()); |`i.8
sHeader=httpConnection.getHeaderFieldKey(i); KQ\d$fX
if(sHeader!=null) 9}DF*np`G
{ .ugQH<B
if(sHeader.equals("Content-Length")) =gb(<`{>
{ Y^P'slY{%
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); L.M|o
break; e:H9!
} ;%tu;
} +HxL>\
else NDaM;`
break; _$Hx:^p:
} 70&]nb6f
} fW'U7&O
catch(IOException e){e.printStackTrace ();} ,BCo/j
catch(Exception e){e.printStackTrace ();} ;r}>1LhN
~0~f
U%,N"]`
Utility.log(nFileLength); wRi` L7
u/8urxpy
&^W91C?<6
return nFileLength; umo@JWr
} _^)<d$R<
;Pi-H,1b
w 9mi2=
//保存下载信息（文件指针位置） A+Xk=k5<
private void write_nPos() k)a-odNrb
{ B "z`X!\
try{ l[EjtN
output = new DataOutputStream(new FileOutputStream(tmpFile)); ?]#U~M<'
output.writeInt(nStartPos.length); i@C$O.m(
for(int i=0;i<nStartPos.length;i++) IO\>U(:vx
{ lV0\UySH
// output.writeLong(nPos); uM^eoh_
output.writeLong(fileSplitterFetch.nStartPos); u0(PWCi2
output.writeLong(fileSplitterFetch.nEndPos); 1E*No1
} krC4O2Fkj
output.close(); .#] V5g,
} x1}7c9nK
catch(IOException e){e.printStackTrace ();} URodvyD
catch(Exception e){e.printStackTrace ();} (IXe555
} M=hH:[6 &
d,G:+
wf<=rW'
//读取保存的下载信息（文件指针位置） KnC;j-j
private void read_nPos() Eo$7W5hJ
{ L]goHs
try{ 65ctxxWv1
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); gqje]Zc<
int nCount = input.readInt(); E,[@jxP
nStartPos = new long[nCount]; E-\<,=bh
nEndPos = new long[nCount]; $EB&]t+
for(int i=0;i<nStartPos.length;i++) -o8H_MR
{ Z. ))=w6G
nStartPos = input.readLong(); 3K/32Wi
nEndPos = input.readLong(); e `!PQMLU
} `N_elf://n
input.close(); ' {L5 3cH=
} (hB&OP5Fne
catch(IOException e){e.printStackTrace ();} 3Ms` ajJ
catch(Exception e){e.printStackTrace ();} H+`s#'(i_P
} b3G4cO;t;
gNdEPaaFI
I6x
private void processErrorCode(int nErrorCode) p9;Oe,Il
{ fWx %?J
System.err.println("Error Code : " + nErrorCode); +0016UgS#
} d;3/Vr$t=
W)dQyZ>J
B&~#.<23:
//停止文件下载 8IYn9<L
public void siteStop() 3[g%T2&[
{ 9Ij=~p]p
bStop = true; [*<F
for(int i=0;i<nStartPos.length;i++) 4!pMZ<$3
fileSplitterFetch.splitterStop(); M^c`j#NQ
c/Fy1Lv\
la7VeFT
} T5; zgr
} jN\} l|;q
//负责部分文件的抓取 $TON`+lB
**FileSplitterFetch.java gOpi>
*/ ,m| :U
package NetFox; 4l/hh|3@
M ABrf`<b
p5|.E
import java.io.*; G%{J.J41F
import java.net.*; :.863_/
4K_rL{s0U
l<5@a (
public class FileSplitterFetch extends Thread { Arg604V3
uhi(Gny.
9yU(ei:GUo
String sURL; //File URL J1@X6U!{
long nStartPos; //File Snippet Start Position <L4.*
long nEndPos; //File Snippet End Position YP*EDb?f
int nThreadID; //Thread's ID {MP8B'r-6
boolean bDownOver = false; //Downing is over r5U[jwP
boolean bStop = false; //Stop identical 3uSj5+@q6
FileAccessI fileAccessI = null; //File Access interface Tm!pAD
?b?6/_W~R
S$ u`)BG):
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException nQe^Bn
{ @>>8CU^~
this.sURL = sURL; 7jss3^.wA
this.nStartPos = nStart; BE`{? -G
this.nEndPos = nEnd; %w+"MkH _
nThreadID = id; [BPK0
fileAccessI = new FileAccessI(sName,nStartPos);//定位 W7bA#p(
} v|IPus|>
q"Ct=d
7R4sd
public void run() Z~&$s
{ N_3$B=
while(nStartPos < nEndPos && !bStop) \"L ;Ct 8
{ rG#o*oA
MIV<"A
6j*L]Sc
try{ ^^q9+0@
URL url = new URL(sURL); D8Ntzsr6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); R,]J~TfPK
httpConnection.setRequestProperty("User-Agent","NetFox"); ,\YlDcl':0
String sProperty = "bytes="+nStartPos+"-"; D<V[:~-o
httpConnection.setRequestProperty("RANGE",sProperty); qDG{hvl[1r
Utility.log(sProperty); fP+RuZ
mEL<d,XhI
JQi+y;
InputStream input = httpConnection.getInputStream(); d-GU164
//logResponseHead(httpConnection); ^("23mhfJ
Z2Q'9C},m
rM?O2n
byte[] b = new byte[1024]; i5PZ)&
int nRead; = aO1uC|6C
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 3pzp6o2
{ Fe r&X
nStartPos += fileAccessI.write(b,0,nRead); BM~>=emc
//if(nThreadID == 1) A_8UPGh8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); /Bt+Ov3k
} x9DG87P~+
%S`ygc}|
N7Kg52|
Utility.log("Thread " + nThreadID + " is over!"); sJI" m'r=Z
bDownOver = true; AVn?86ri
//nPos = fileAccessI.write (b,0,nRead); M%yeI{m
} 4Nb&(p
catch(Exception e){e.printStackTrace ();} 0A,u!"4[
} TnuaP'xZ
} =c(t;u6m-
!iNN6-v%
!t;B.[U *
//打印回应的头信息 sYfiC`9SO
public void logResponseHead(HttpURLConnection con) /8cfdP Ba
{ o4.?m6d
for(int i=1;;i++) =<BPoGs5
{ Th'B5:`
String header=con.getHeaderFieldKey(i); dmB _`R
if(header!=null) nB|m!fi<
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 5bj9S
Utility.log(header+" : "+con.getHeaderField(header)); Eo) #t{{
else ln1QY"g
break; 9}*Pb6
} 3D}rxI8N
} Il4R R
Md*~hb8J
)yTBtYw3
public void splitterStop() *3!#W|#=]N
{ 2Wx~+@1y
bStop = true; ^~7/hm:
} -d*zgP
7l+:gD
WV8vDv1jt
} DtFzT>$^F
XU*4MU^'
(i.7\$4
/* #dj,=^1_14
**FileAccess.java W<c95QD.
*//文件访问(定位，写) GbwqrH+
package NetFox; NI^jQS M]
import java.io.*; FoX,({*Ko~
%7v!aJ40
7L4~yazmK
public class FileAccessI implements Serializable{ 5OM*NT t
K/l*Saj
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 th^&wp
RandomAccessFile oSavedFile; DedY(JOvB
long nPos; 4(%LG)a4S
OnND(YiX
\sEH)$R'
public FileAccessI() throws IOException `gX$N1(
{ IJk<1T7:(W
this("",0); DyCnL@
} :>*0./hG
0..]c-V(G
F T$x#>
public FileAccessI(String sName,long nPos) throws IOException Vv_lBYV
{ .L8g(F(=:
oSavedFile = new RandomAccessFile(sName,"rw"); S7h?tR*u
this.nPos = nPos; >*h3u7t
oSavedFile.seek(nPos); 43s8a
} ~[Z,:=z
jAxrU
/_!Ed]
public synchronized int write(byte[] b,int nStart,int nLen) @ruWnwb
{ y1bo28
int n = -1; PlRcrT"#w
try{ V)Ze>Pp
oSavedFile.write(b,nStart,nLen); Lk]W?
n = nLen; Nz%Yi?AF
} /wPW2<|"X.
catch(IOException e) B&"c:)1 C2
{ 6B!v;93U
e.printStackTrace (); 7_~_$I~g*
} -u^f;4|u
4Cp)!Bq?/
X@\ 9}*9
return n; UgTgva>?
} v!j%<H`NI
C#@-uo2
}=fls=c/0
} Ge ?Q)N
cuh Z_l
Sr>5V
/* J]5ZWo%
**SiteInfoBean.java ,0aRHy_^
*/ tPChVnB
package NetFox; D77s3AyHK
b!T-{Ns6
e3WEsD+
public class SiteInfoBean { T:3}W0s,
"""pe+Y
h$#|s/
private String sSiteURL; //Site's URL o('6,D
private String sFilePath; //Saved File's Path Tbj}04;I
private String sFileName; //Saved File's Name vlo!D9zsV3
private int nSplitter; //Count of Splited Downloading File Ga\kvMtr
J@qwz[d i
U nS|""
public SiteInfoBean() ,[[Xo;q
{//nSplitter的缺省值为5 LY2QKjgP
//default value of nSplitter is 5 xiO10:L4
this("","","",5); @c=bH>Oz
} w"Y'I$
NdB:2P
"QmlW2ysi
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) zYEb#*Kar
{ GpCjoNcW{
sSiteURL= sURL; A\v]ZN4
sFilePath = sPath; >NZJ-:t
sFileName = sName; MPMAFs
this.nSplitter = nSpiltter; >2mV{i&
Bp/25jy
\9 k3;zw
} !H(V%B%
[_HOD^
^-,@D+eW
public String getSSiteURL() 8@]vvZ2/gj
{ P9M. J^<
return sSiteURL; R(IYb%L
} Jp(CBCG{F
*z__$!LR
}^azj>p5
public void setSSiteURL(String value) zd3^k<
{ T&->xef=
sSiteURL = value; R_Uy.0=4
} uHPd!#]
HxNoV.q
w~>tpkUB
public String getSFilePath() ]%+T+zg(Y
{ :_kZkWD5
return sFilePath; z0?IQzR^T
} vA*Q}]Ov
;]_h")4"c
KVPWJHGr
public void setSFilePath(String value) z)%]#QO
{ 2I{kLN1TY
sFilePath = value; ]\*_}
} $t.M`:G
Nq#B4Zx
`{xKU8j^
public String getSFileName() rVB\\
{ a&<_M$J&
return sFileName; FBS]U$1
} 0HDL;XY6
qD{~QHDa
n"f:6|<
public void setSFileName(String value) QZFH>,d
{ TnJNs
sFileName = value; af|x(:!H
} "8/BVW^bv
wS+j^ ;"
6@Ir|o
public int getNSplitter() fzzk#jU
{ L4v26*P
return nSplitter; ?4#wVzuzA
} U|+c&TY
O#Ho08*Xn
a=M/0N{!
public void setNSplitter(int nCount) YA~`R~9d
{ 9]QHwa>_|2
nSplitter = nCount; kn}bb*eZ
} 3Hf_!C=g
} r>J%Eu/O
mLDuizWI
G|qsJ
/* =J'&.@Dwz
**Utility.java 'k/:3?R
*/ $~NB .SY
package NetFox; *z)+'D*+
pV/5w<_x?
X-`PF
public class Utility { vPD%5AJN
Ys8D|HIk
H6<3'P
public Utility() Z5,"KhB]
{ *|6*jU
K9) |b`E=
IgPU^?sp
} >Zh^,T={G
vGchKN~_
//线程睡眠 ,D\}DJ`)C
public static void sleep(int nSecond) M2LW[z
{ D;6C2>U~L
try{ .J\i!
Thread.sleep(nSecond); 3V3q vd
} cQ(,M
catch(Exception e) wexa\o
{ !r4B1fX
e.printStackTrace (); /@@?0xjX
} ]P)2Q!X
} @*iT%p_L
lhB;jE
//日志 ORFi0gFbA
public static void log(String sMsg) #=#bv`
{ C^*}*hYk$
System.err.println(sMsg); 8" (j_~;
} )TwA?kj
W/u_<\
tD6ukK1x
public static void log(int sMsg) Xuj=V?5
{ 6yXN7L==x
System.err.println(sMsg); +5H1n(6)
} ,AG k4]
} `2n%Lo?_
(} Y|^uM,
&"clBRVg
/* __[bKd.
**TestMethod.java A#nSK#wS61
*/ .cs4AWml<
package NetFox; 0">9n9
vxXrVPU3
CW?R7A/
public class TestMethod { LNM#\fb
x{1S!A^
O]G3l0
public TestMethod() K.42 VM)F
{ ///xx/weblogic60b2_win.exe pI}6AAs}Z
try{ N`+@_.iBX
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); i?6#>;f
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); x,#?
SiteFileFetch fileFetch = new SiteFileFetch(bean); T5>'q;jM
fileFetch.start(); \!zM4ppr
} \6vr)1~N>
catch(Exception e){e.printStackTrace ();} tfPe-U
\8/$ZEom
M~5Ja0N~
} j~#v*qmDU
t?h\Af4Tf
5N$O
public static void main(String[] args) '(SqHP|8&g
{ i(0%cNP7
new TestMethod(); ML:H\
} R'h.lX
} W!)B%.Q
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