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)); \tQRyj\|
} &"d4J?io`
for(int i=0;i<nEndPos.length-1;i++) v!W,h2:J
{ za24-q
nEndPos = nStartPos[i+1]; =n;ileGm+^
} &3AGj,
nEndPos[nEndPos.length-1] = nFileLength; /at#[Pw~01
} }U8H4B~UtY
} j| 257D
{6~W2zX&
DTJ~.
//启动子线程 wD*_S}]
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; =!p6}5Z
for(int i=0;i<nStartPos.length;i++) &gq\e^0CRZ
{ 1W;+hXx
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Ex~OT
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), inp=-
nStartPos,nEndPos,i); ;8UNM
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); `f b}cJUa
fileSplitterFetch.start(); s'i1!GNF B
} jtd{=[STU
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \n/_Px
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 8 2_3|T
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", 5~ jGF
nEndPos = " + nFileLength); ^D\#*pIO
// fileSplitterFetch[nPos.length-1].start(); ~(FyGB}
fa$ Fo(.
{At1]>
//等待子线程结束 &ts!D!Hj
//int count = 0; S c@g;+#QU
//是否结束while循环 5<&<61[A
boolean breakWhile = false; 8pPAEf
qG~O]($
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while(!bStop) d]+g3oy `
{ G`w7dn;&
write_nPos(); dGZVWEaPfx
Utility.sleep(500); * \f(E#wa
breakWhile = true; $S6AqUk$
1!,lI?j,
rjfQ\W;}U
for(int i=0;i<nStartPos.length;i++) ]W]Vkkg]
{ w!tQU9+*
if(!fileSplitterFetch.bDownOver) UiW(/L
{ Z1*y$=D?3[
breakWhile = false; :h?Zg(l
break; +xB!T1pD
} R$NH [Tz
} ;clF\K>
if(breakWhile) ,HR~oT^
break; dxxD%lHCF
"o%N`Xlx
=|=9\3po
//count++; 5,;{<\c
//if(count>4) %I[(`nb
// siteStop(); omY%sQ{)
} )}vQ?n[:'
HIeWgw^"
IZniRd;
System.err.println("文件下载结束！"); Z=4Krfn
} 8gr&{-5
catch(Exception e){e.printStackTrace ();} &A]*"lt|w
} >\%44ba6
^o65sM
nSmYa7
//获得文件长度 "\]kK@,
public long getFileSize() DSD#',
{ {SJ=|L6
int nFileLength = -1; f!eC|:D
try{ DTsc&.29^
URL url = new URL(siteInfoBean.getSSiteURL()); F[ m^(x
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); i8+kc_8#d
httpConnection.setRequestProperty("User-Agent","NetFox"); tihb38gE
X Oc0j9Oa
*!Vic#D%
int responseCode=httpConnection.getResponseCode(); A<QYW,:|
if(responseCode>=400) )k- 7mwkZ
{ VNx}ADXu]
processErrorCode(responseCode); e*:[#LJ]C
return -2; //-2 represent access is error E&jngxlN
} mRxL%!
>{$;O
qXCl6Yo8
String sHeader; :Dw;RcZQ
s=u0M;A0Q
S\MD]>4
for(int i=1;;i++) 45>w=O
{ LX!16a@SxA
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); -;_NdL@
//Utility.log(in.readLine()); M +~guTh
sHeader=httpConnection.getHeaderFieldKey(i); WQ|d;[E
if(sHeader!=null) lKxv SyD
{ i=#r JK=
if(sHeader.equals("Content-Length")) u,*$n'l]
{ )j]S;Mr
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); Lb{~a_c
break; !s9<%bp3
} `9kjYSd#E
} 7a->"W
else >/ECLP
break; 'h([Y8p{
} f@Hp,-
} --dGN.*xb4
catch(IOException e){e.printStackTrace ();} /Vg R[
catch(Exception e){e.printStackTrace ();} mv)M9c,`
N|WnUlf]:
qd%5[A
Utility.log(nFileLength); P)tXU
sO~N2
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return nFileLength; Cx} Yp-
} oy;N3
4qrPAt
kZWc(LwA
//保存下载信息（文件指针位置） l)Q,*i
private void write_nPos() bv)E>%Yy
{ Z:&"Ax
try{ b^;19]/RW
output = new DataOutputStream(new FileOutputStream(tmpFile)); t9zPJQlT}
output.writeInt(nStartPos.length); GKZn|<Y|{c
for(int i=0;i<nStartPos.length;i++) axxdW)+K
{ @$F(({?
// output.writeLong(nPos); acRPKTs H
output.writeLong(fileSplitterFetch.nStartPos); jgs kK
output.writeLong(fileSplitterFetch.nEndPos); ]j}zN2[A
} iePpJ>(
output.close(); eWhv X9 <
} {Ejv8UdA9
catch(IOException e){e.printStackTrace ();} !3-mPG< ]
catch(Exception e){e.printStackTrace ();} Cc1sZWvz
} P zzX Ds6
:2 n5;fp
t'Nu^_#
//读取保存的下载信息（文件指针位置） Qo0okir
private void read_nPos() o%+KS5v!
{ d_QHm;}Cx
try{ a+{YTR>0m
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); (|I0C 'Ki
int nCount = input.readInt(); ;^=eiurv
nStartPos = new long[nCount]; w-HgC
nEndPos = new long[nCount]; ~lzV=c$t
for(int i=0;i<nStartPos.length;i++) >hRYsWbmg
{ KJ.ra\F
nStartPos = input.readLong(); ST'L \yebc
nEndPos = input.readLong(); 2Qc&6-;`
} SrN0f0
input.close(); ad&Mk^p
} st:[|`
catch(IOException e){e.printStackTrace ();} XaR(q2s
catch(Exception e){e.printStackTrace ();} 'N,x=1R5
} )tz8(S
i5(_.1X<#{
t8U)za
private void processErrorCode(int nErrorCode) TEE$1RxV(
{ RCND|X
System.err.println("Error Code : " + nErrorCode); Njc3X@4=
} Y\%R6/Gj|u
^r(2 r
j &)|nK;}
//停止文件下载 |2 g }i\
public void siteStop() Z@t).$
{ U:J~Oy_Z
bStop = true; 7 G~MqnO|
for(int i=0;i<nStartPos.length;i++) h%E25in
fileSplitterFetch.splitterStop(); ' f}^/`J
X`.4byqdK
'355Pce/
} ?F(t`0=
} MP w@O0QS
//负责部分文件的抓取 q^n6"&;*
**FileSplitterFetch.java cJ&l86/l1
*/ *[.+|v;A
package NetFox; ceH7Rq:4W
+S<2d.&~
tqmM7$}}P
import java.io.*; oHxaa>C>
import java.net.*; fdck/|`t
xPq3Sfg`A
"P&|e|7
public class FileSplitterFetch extends Thread { 1k-^LdDj
nm*1JA.:
{S~2m2up0L
String sURL; //File URL '"GdO;}&
long nStartPos; //File Snippet Start Position 6:330"9
long nEndPos; //File Snippet End Position {SqY77
int nThreadID; //Thread's ID P`-(08t
boolean bDownOver = false; //Downing is over P7 (&*=V
boolean bStop = false; //Stop identical fx99@%Ii
FileAccessI fileAccessI = null; //File Access interface S]K^wj[
2^[fUzL?
|jEKUTv,G
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException DS=kSkW^&5
{ n"@3d.21
this.sURL = sURL; ;}.jRmnJ
this.nStartPos = nStart; nDMNaMYb
this.nEndPos = nEnd; /(W{`
nThreadID = id; !CPv{c`|qg
fileAccessI = new FileAccessI(sName,nStartPos);//定位 l.;y`cs
} ?9Fv0-g&n
uQ5NN*C=
m&Ms[X
public void run() '+f!(teLz
{ dK|MQ <
while(nStartPos < nEndPos && !bStop) NO`LSF
{ C/<fR:`c
feQ_dA q
o!sxfJKl
try{ rYJt;/RtR}
URL url = new URL(sURL); jcXb@FE6
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); L7X._XBO[
httpConnection.setRequestProperty("User-Agent","NetFox"); TcauCL
String sProperty = "bytes="+nStartPos+"-"; IR5 S-vO
httpConnection.setRequestProperty("RANGE",sProperty); $daI++v`
Utility.log(sProperty); KD-0NO=oL
AJCWp4,
g#Zb}^
InputStream input = httpConnection.getInputStream(); BL]!j#''KE
//logResponseHead(httpConnection); yoGE#+|7^
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V=3NIw18
byte[] b = new byte[1024]; _^#PV}
int nRead; T_5 E
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) WuSRA<{P
{ o1GWcxu*\
nStartPos += fileAccessI.write(b,0,nRead); }{=%j~V;&
//if(nThreadID == 1) Vn=J$Uv0
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); qW;nWfkYC
} XLEA|#
ln3x1^!
(0Hhn2JA
Utility.log("Thread " + nThreadID + " is over!"); 0t/S_Q
bDownOver = true; 0:v7X)St
//nPos = fileAccessI.write (b,0,nRead); P:ys--$"
} T/-PSfbkj
catch(Exception e){e.printStackTrace ();} o"7,CQye
} w?oIKj
} IW6;ZDP
*`|.:'
cMC1|3
//打印回应的头信息 iT 4H@
public void logResponseHead(HttpURLConnection con) ndF Kw
{ IBES$[
for(int i=1;;i++) ?#J~X\5
{ 'ZL)-kbI
String header=con.getHeaderFieldKey(i); 9I]*T
if(header!=null) OFQsfW3O
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 9 r+' o#
Utility.log(header+" : "+con.getHeaderField(header)); dkG-Yz~
else ,i>5\Yl%
break; U~Uxs\0:
} luat1#~J
} FZjtQ{M
k}F;e_
(a&.Ad0{
public void splitterStop() Ev*HH+:b>
{ N<$uAns
bStop = true; UCvMW*gs
} wQPjo!FEX
Z~T- *1V
:S~XE
} @HIC i]
N@tzYD|hA
/vsQ <t;~
/* J*a`qU
**FileAccess.java `=q)-y_C
*//文件访问(定位，写) +SUQRDF@i
package NetFox; Yw?%>L
import java.io.*; JfKl=vg
0sV;TQt+f
w y:USS?
public class FileAccessI implements Serializable{ pBK[j([
> {fX;l
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 mR8&9]g&
RandomAccessFile oSavedFile; gmJJ(}HVz
long nPos; 3o"~_l$z
R%7k<1d'`
-qid.
public FileAccessI() throws IOException =1`
{ M#F;eK2pf
this("",0); }{j[
} ;M@/AAZ
5:^dyF&sm{
MFE~bU(h
public FileAccessI(String sName,long nPos) throws IOException )7c^@I;7
{ 6M612
oSavedFile = new RandomAccessFile(sName,"rw"); N-_2d*l3
this.nPos = nPos; ymr-kB
oSavedFile.seek(nPos); G78rpp
} ew}C*4qH
}1X,~y]
A g/z\kX
public synchronized int write(byte[] b,int nStart,int nLen) 9FJU'$FN
{ h+N75
int n = -1; $Iqt c)DA
try{ T][\wyLx1
oSavedFile.write(b,nStart,nLen); Q\ro )r
n = nLen; 33"{"2==`
} 2&Wc4,O!i
catch(IOException e) qI5/ME(}
{ -!wm]kx f
e.printStackTrace (); {#>@h7
} lt}|Y9h
V, )kw{](
Z{u*vUC&
return n; VpTp*[8O
} ]J_Dn\
2E=E!Zwt_
ffuV$#
} lEQn2+
@}aK\
$n(@hT>?
/* S\g8(\u
**SiteInfoBean.java mP3:Fc_G
*/ Q:=s99
package NetFox; u) fbR
BX+-KvT
i aP+Vab
public class SiteInfoBean { Z1^S;#v
?A,gDk/#
8.]dThaq
private String sSiteURL; //Site's URL vP88%I;
private String sFilePath; //Saved File's Path 2 B5kpmH:
private String sFileName; //Saved File's Name @f{)]I +f
private int nSplitter; //Count of Splited Downloading File - DL/Hk_r
KWN0$*4
ke)3*.Y%C
public SiteInfoBean() "o=h /q5&
{//nSplitter的缺省值为5 .o.@cLdU
//default value of nSplitter is 5 jf.ikxm
this("","","",5); D@O'8
} 8l;0)`PU
{7B$%G'
OO53U=NU
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) gt{ei)2b
{ TZ-n)rC)v
sSiteURL= sURL; tEBf2|<
sFilePath = sPath; +>c)5Jih
sFileName = sName; pEhWgCL
this.nSplitter = nSpiltter; !Bu<6
|wVoJO!O}
UmInAH4
} R1J"QU
0&-!v?6)
eJ2[=L'
public String getSSiteURL() dtm_~r7~
{ `I_%`15>
return sSiteURL; ~>s^/`|?
} < ~x5{p
FW[<;$
IExQ}I
public void setSSiteURL(String value) l|j&w[c[Q0
{ D zl#[|q
sSiteURL = value; 7d'4"c;*;
} * Oyic3F
^_)CQ%W?
EUUj-.dEN
public String getSFilePath() kc/h]B
{ <~X=6
return sFilePath; M8S4D&vpD4
} fs>0{
lKH"PH7*_w
Gash3}+
public void setSFilePath(String value) N|7<*\o
{ "0zMx`Dh
sFilePath = value; D.R5-
} %#ms`"H
/KlA7MH6
=eTI@pN`
public String getSFileName() -+Quw2465^
{ `C_#EU-
return sFileName; 98o;_tU'
} {&w%3
}wj*^>*
)k29mqa`
public void setSFileName(String value) kD MS7y<s
{ ( 9dV%#G\
sFileName = value; wyAqrf
} EX8]i,s|E
Mk,8v],-Tj
kDO6:sjR7
public int getNSplitter() fbo64$!hZ
{ `acorfpi
return nSplitter; :qgdn,Me
} 6TPcG dZ
,FS iE\
SuGlNp>#qm
public void setNSplitter(int nCount) A(;J
{ d'Gv\i&e
nSplitter = nCount; 69yTGUG3
} '{6`n5:e
} Wu.od|t0
If!0w ;h
z-$?.?d
/* J8? 6yd-7
**Utility.java CdTmL{Y1
*/ `2r21rVntf
package NetFox; t$Irr*
B>a`mFM
]~kqPw<R
public class Utility { >{Lfrc1
#J^p,6
D|9B1>A,m
public Utility() ub4(mS
{ Y5ebpw+B-
pok,`yW\
*;"^b\f5_
} 0#Rj[J;kh
zS?i@e $
//线程睡眠 :CK,(?t
public static void sleep(int nSecond) pklcRrx,a
{ b'vJPv~hI
try{ #c/v2
Thread.sleep(nSecond); vbwEX6
} hw~cS7
catch(Exception e) BIV]4vl-&
{ r=&PUT+vt
e.printStackTrace (); 0b*a2_|8k
} Z][?'^`^!
} n!HFHy2
vc^PXjX
//日志 9Cf^Q3)5o
public static void log(String sMsg) e$F7wto
{ 1{";u"q
System.err.println(sMsg); <!DOCvd
} 8'g/WZY~~
nW|[poQK
m\@Q/_v
public static void log(int sMsg) +H="5uO<
{ V!FzVl=G
System.err.println(sMsg); ]p0m6}B
} 2px5>4<
} \ 0<e#0-V
%$sWNn
pR\etXeLd
/* /hI#6k8o_
**TestMethod.java _Q.3X[88C
*/ kAy.o
package NetFox; 8 LaZ5
O8dDoP\F2
I X\&lV
public class TestMethod { m^]/ /j
f<kL}B+,Og
<;U"D.'
public TestMethod() cpE&Fba}"
{ ///xx/weblogic60b2_win.exe wQ[2yq
try{ uLL#(bhDr
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); Z|wZyt$$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); *+@/:$|U
SiteFileFetch fileFetch = new SiteFileFetch(bean); 7*[>e7:A
fileFetch.start(); vO4 &ZQ>6
} kO2im+y
catch(Exception e){e.printStackTrace ();} WQ"ZQ
#NL1N_B
zROyG
} D-,sF8{ i
Saz+GQ G
Zjo9c{\
public static void main(String[] args) df8rf8B-
{ `L9o!OsQ
new TestMethod(); 2ix_,yTO
} Yq5}r?N
} sV[|op
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