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)); 72,iRH
} y%,BDyK
for(int i=0;i<nEndPos.length-1;i++) :9YQX(l8
{ -0X> y
nEndPos = nStartPos[i+1]; )mPlB.
} 1}uDgz^
nEndPos[nEndPos.length-1] = nFileLength; z )pV$
} I7~|!d6
} =z3jFaZ
9A_7:V]_
/)I9+s#q9o
//启动子线程 vvM)Rb,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6-=_i)kzq
for(int i=0;i<nStartPos.length;i++) }gW}Vr <
{ 7asq]Y}<
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XJzXxhk2
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ".)_kt[
nStartPos,nEndPos,i); O$H150,Q
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H+;wnI>@
fileSplitterFetch.start(); YzZF^q^I
} WNb$2q=
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), RrHnDO'
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); EDo@J2A
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", @(cS8%wK
nEndPos = " + nFileLength); xB(:d'1|
// fileSplitterFetch[nPos.length-1].start(); x]ti3?w
6b/b}vl
':V_V. :
//等待子线程结束 ]1&9~TL
//int count = 0; ~{+{pcO}
//是否结束while循环 h2%:;phH
boolean breakWhile = false; >.iw8#l
/=@vG Vp6
%&Cl@6
while(!bStop) _o.Z`]
{ 4iz&"~&1
write_nPos(); ]K7 64}
Utility.sleep(500); /Xz4q!Ul
breakWhile = true; +*J4q5;E[?
dNQSbp
vy@Lu cB
for(int i=0;i<nStartPos.length;i++) pD#"8h
{ doc
if(!fileSplitterFetch.bDownOver) aHC;p=RQ\A
{ ?X'* p<`
breakWhile = false; ?i~/gjp
break; (@E#O$'
} "Cc"y* P
} S7a6ntei
if(breakWhile) C):d9OI?
break; zb/Xfu.)?6
@WHd(ka!
@S7=6RKa[
//count++; H040-Q;S'
//if(count>4) =BS'oBn^6
// siteStop(); XQOprIJ U
} F?} *ovy
udGGDH
f hG2
System.err.println("文件下载结束！"); }qv-lO
} XyphQ}\u
catch(Exception e){e.printStackTrace ();} C[nr>
} ? SP7vQ/
-^H5z+"^
~{YgM/c|dt
//获得文件长度 :WIf$P?X
public long getFileSize() WWcm(q=
{ Noxz kpMF
int nFileLength = -1; ?0NSjK5ma
try{ Ro]IE|Fv
URL url = new URL(siteInfoBean.getSSiteURL()); 9'q/&uH
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); <88}+j
httpConnection.setRequestProperty("User-Agent","NetFox"); hZWK5KwT
|u;BAb
/JeqoM"x
int responseCode=httpConnection.getResponseCode(); hu(K!>{
if(responseCode>=400) `_U0>Bfg;
{ FRt/{(jro
processErrorCode(responseCode); Zk#i9[g9*
return -2; //-2 represent access is error m]d6@"Z.
} ^Cn]+0G#C8
Kw0V4UF
0~b6wuFl
String sHeader; e K1m(E.=
pE/3-0;}N
MD4 j~q\g
for(int i=1;;i++) 1IQOl
{ +Z&&H'xD
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); z%3"d0
//Utility.log(in.readLine()); Jf<yTAm
sHeader=httpConnection.getHeaderFieldKey(i); q>(u>z!
if(sHeader!=null) 7Y|>xx=v
{ $a*Q).^
if(sHeader.equals("Content-Length")) c9TAV,/fF*
{ bNjaCK<
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); fC GDL6E
break; ?VZXJO{^
} qb>r\bc
} T0v@mXBQ
else $;i$k2n:
break; 60%~+oHi~
} T:%wX9W
} PnIvk]"Ab
catch(IOException e){e.printStackTrace ();} FP9<E93br
catch(Exception e){e.printStackTrace ();} g~hk-nXL.
d<GG(
q\t>D _lU
Utility.log(nFileLength); *DCNu{6
FR,#s^kF
sx<+ *Trl
return nFileLength; <<On*#80w
} 0S:!Gv+
|z|)r"*\4
\v3>Eo[
//保存下载信息（文件指针位置） |@L &yg,x
private void write_nPos() *_/eAi/WG
{ G'?f!fz;
try{ 7cmr *y
output = new DataOutputStream(new FileOutputStream(tmpFile)); 5f&{!N
output.writeInt(nStartPos.length); , HI%Xn
for(int i=0;i<nStartPos.length;i++) VWA-?%r
{ [^d6cMEOlc
// output.writeLong(nPos); ok%a|Zz+]
output.writeLong(fileSplitterFetch.nStartPos); z?uQlm*We
output.writeLong(fileSplitterFetch.nEndPos); aRO_,n9
} -~O;tJF2
output.close(); 9g&)6,<
} tct5*.|
catch(IOException e){e.printStackTrace ();} =PKt09b^
catch(Exception e){e.printStackTrace ();} ssX6kgq_(
} @)Hbgkdi
E}b>7L&w
W3{<e"
//读取保存的下载信息（文件指针位置） YNgR1:l
private void read_nPos() 9CK\tx&
{ OwiWnS<
try{ gvc' $9%
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); @@{_[ir
int nCount = input.readInt(); ^,Y~M_=
nStartPos = new long[nCount]; ^W[B[Y<k
nEndPos = new long[nCount]; ghobu}wuF
for(int i=0;i<nStartPos.length;i++) |6(qg5"
{ llaZP(pJ
nStartPos = input.readLong(); Avv
nEndPos = input.readLong(); =Mu'+,dT
} ~0[G/A$]
input.close(); 4&]To@>
} )>/j&>%
catch(IOException e){e.printStackTrace ();} ^tg6JB;s
catch(Exception e){e.printStackTrace ();} !: EW21m
} Qk~0a?#y5
]IHD:!Z-=
+NLQYuN
private void processErrorCode(int nErrorCode) fJn3"D'
{ 7\0|`{|R@
System.err.println("Error Code : " + nErrorCode); \p3nd!OIG
} PD}SPOA`U3
+1+A3
=2g[tsY
//停止文件下载 =Qj+Ug'
public void siteStop() Qor{1_h)+9
{ Yn$>QS 4
bStop = true; SD|4ybK>d
for(int i=0;i<nStartPos.length;i++) 8!&ds~?
fileSplitterFetch.splitterStop(); =Y]'5cn{
,Og[[0g
VO @ 4A6
} 3<jAp#bE
} 1fO2)$Y
//负责部分文件的抓取 fUp|3bBE
**FileSplitterFetch.java }/7.+yD
*/ q1H~ |1
package NetFox; e"*BHvy F
]Qd{ '}+
dl:-k r8
import java.io.*; UIQQ\,3
import java.net.*; ~ W@X-
:]yg
p7s@%scp
public class FileSplitterFetch extends Thread { tzPC/?
h(_P9E[g
\WcB9
String sURL; //File URL [ne" T
long nStartPos; //File Snippet Start Position 4b]_ #7Qm
long nEndPos; //File Snippet End Position Yhe+u\vGs\
int nThreadID; //Thread's ID "2%>M
boolean bDownOver = false; //Downing is over sA3UeTf
boolean bStop = false; //Stop identical k'g$2
FileAccessI fileAccessI = null; //File Access interface p<q].^M
c& 3#-DNI
<8f(eP\*F
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException u %'y_C3
{ U7E
this.sURL = sURL; o_sQQF
this.nStartPos = nStart; .?B{GnB>
this.nEndPos = nEnd; l^ARW E
nThreadID = id; wEE2a56L-
fileAccessI = new FileAccessI(sName,nStartPos);//定位 6p#g0t
} EA6t36|TX
+GYS26
]Dh1~k.Kp
public void run() 8-ZUS|7B
{ <.}Ua(
while(nStartPos < nEndPos && !bStop) wDMjk2YN
{ Ssw&'B|o
#\LZ;&T'N
Nl {7
try{ U~wjR"='
URL url = new URL(sURL); JIMWMk;ot
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); o*-9J2V=J
httpConnection.setRequestProperty("User-Agent","NetFox"); C-Ig_Nc
String sProperty = "bytes="+nStartPos+"-"; La9r
httpConnection.setRequestProperty("RANGE",sProperty); eHUg-\dy
Utility.log(sProperty); G,=F<TnI'
Hng!'
#MglHQO+
InputStream input = httpConnection.getInputStream(); U-eI\Lu
//logResponseHead(httpConnection); 3?@?-q2g
0Qp[\ia
Fom>'g*
byte[] b = new byte[1024]; Z["BgEJ
int nRead; I(n }<)eF
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) p-,Iio+
{ S.W^7Ap
nStartPos += fileAccessI.write(b,0,nRead); mL$f[
//if(nThreadID == 1) v77fQ0w3
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S7CV w,2
} 'l|R5
+bUW!$G
ljVIE/iq
Utility.log("Thread " + nThreadID + " is over!"); =e{.yggE
bDownOver = true; nkRK+~>
//nPos = fileAccessI.write (b,0,nRead); E?cZbn*>`
} L<=)@7
catch(Exception e){e.printStackTrace ();} (UGol[f<
} 'B`#:tX^N
} c" +zgP
#]y5zi
Tm_8<$ 7
//打印回应的头信息 =JW[pRI5a
public void logResponseHead(HttpURLConnection con) f?^S bp
{ f`?0WJ(M
for(int i=1;;i++) #uKWuGz]
{ H2U:@.o2&
String header=con.getHeaderFieldKey(i); M&f#wQ
if(header!=null) RLHYw@-j@
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ybE[B}pOeZ
Utility.log(header+" : "+con.getHeaderField(header)); W$'0Dc
else 8+>\3j
break; Bc<n2 C0
} TF\sP8>V
} 5kn+ >{jh`
|1Hc&
0% +'
public void splitterStop() 8_a3'o%5
{ !y. $J<
bStop = true; \I:.<2i
} {cR=N~_EO
+c) TDH
C ) ?uE'
} Kt6>L5:94
c`jDW S
PS@*qTin
/* Ri @`a
**FileAccess.java 1 i3k
*//文件访问(定位，写) NR3`M?Hjf
package NetFox; =9$mbn r
import java.io.*; 'zxoRc-b@N
"Pj}E=!k
J +q|$K6
public class FileAccessI implements Serializable{ YeyGN
mmP U
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 L/i(KF{
RandomAccessFile oSavedFile; ARWZ; GX
long nPos; D:JS)+]
9i%9
wf9z"B
public FileAccessI() throws IOException +EkW>$
{ ?WHy0x20
this("",0); _a5(s2wq+
} `R+,1"5=
e&1\'Zq?>
Mu2`ODe]
public FileAccessI(String sName,long nPos) throws IOException OCK>%o$[
{ pM2a(\K,k^
oSavedFile = new RandomAccessFile(sName,"rw"); m@\ZHbq
this.nPos = nPos; re`t ]gzb
oSavedFile.seek(nPos); <3Gqv9Y&
} :=fvZAWD
iM5vrz`n
9Cvn6{
public synchronized int write(byte[] b,int nStart,int nLen) ;LMWNy4
{ c1%rV`)]
int n = -1; _|zBUrN
try{ 62\&RRB i
oSavedFile.write(b,nStart,nLen); XYfv(y
n = nLen; KDTDJ8
} q3S+Y9L
catch(IOException e) ST;t, D:
{ &&7r+.Y
e.printStackTrace (); Oy_c
} f*fE};
&HDP!SLS
[BDGR B7d"
return n; &tE.6^F
} /k6fLn2;
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Yc;ec9~
} n7l%gA*
RiR:69xwR*
e;ty!)]
/* >EP(~G3u
**SiteInfoBean.java 4["&O=:d
*/ s|-FH X
package NetFox; ( u`W!{1\
HOZRYIQB
!'0S0a8
public class SiteInfoBean { 8)wt$b
s9j7Psd
PDP[5q r
private String sSiteURL; //Site's URL "A[ b rG
private String sFilePath; //Saved File's Path |d}MxS`^
private String sFileName; //Saved File's Name UtJa3ya
private int nSplitter; //Count of Splited Downloading File `78V%\
.CbGDZ
1-VT}J(
public SiteInfoBean() NlF}{
{//nSplitter的缺省值为5 'q{733o
//default value of nSplitter is 5 Vrp[r *V@E
this("","","",5); 'C>U=cE7
} ]RIVc3?;$
xf,5R9g/
W?XizTW
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 1*Ar{:+ua
{ `G$1n#&
sSiteURL= sURL; .}`hCt08
sFilePath = sPath; ig_2={Q@
sFileName = sName; :i*JnlvZ
this.nSplitter = nSpiltter; )=^w3y
`<fh+*
9uYyfb: ,z
} HeA{3s
OB^Tq~i
\a|L/9%
public String getSSiteURL() ~<9{#uM
{ RBGX_v?
return sSiteURL; v:|(8Y
} )qU7`0'8
(@sp/:`6
R,_d1^|*w
public void setSSiteURL(String value) >e&:`2%.
{ -?a<qa?$
sSiteURL = value; GWP dv
} p>*i$
P?ep]
Re=WfG
public String getSFilePath() q4k@l
{ P0GeZ02]
return sFilePath; ,FQK;BU!lh
} NAr1[{^E,
d&(_|xq#
n$)_9:Z-j
public void setSFilePath(String value) Mz=!w]qDH
{ HOi C
sFilePath = value; A74920X`W
} ,|T7hTn=
-yx/7B5@
nU z7|y
public String getSFileName() NgZUnh3{
{ !<\Br
return sFileName; v"Jgw;3
} 5OP`c<
}_OM$nzj
fI|[Z+"
public void setSFileName(String value) x"4%(xBu
{ d/,E2i{I7
sFileName = value; 8cxai8
} NAFsFngqH
8cWZ"v
k|E]YvnfG
public int getNSplitter() @gfDp<
{ RW7(r/C
return nSplitter; 7C,T&g 1:
} IB5BO7J
;N=G=X|}
n!ok?=(kQ
public void setNSplitter(int nCount) !K0JV|-?t
{ cma*Dc
nSplitter = nCount; -$a>f4]
} 0@=MOGQb
} HAB#pd9
$#NQ<3
sd0r'jb
/* 6[dur'x
**Utility.java @,H9zrjVFZ
*/ u5E]t9~Pq
package NetFox; Rm>^tu -
j|(Z#3J
&Ral+J
public class Utility { w!3>N"em
/2uQCw&x-
+Ov2`O8?
public Utility() pa]"iZz
{ ~oD8Rnf
m:CTPzAt
y=sGe!^
} 9s$U%F6}
&eZfQ27$
//线程睡眠 1cJsj
public static void sleep(int nSecond) o|8`>!hF
{ t}p@:'
try{ HK=[U9 o?
Thread.sleep(nSecond); NX6nQ
} x5si70BKC/
catch(Exception e) tbDoP Y
{ E+xuWdp.*
e.printStackTrace (); pw020}`
} i^"+5Eq[D
} U9d:@9Y
}ZOFYu0f
//日志 @ GDX7TPV
public static void log(String sMsg) QB{rVI>mI!
{ }xb=<
System.err.println(sMsg); d5j_6X
} h#}YKWL
arZ@3]X%a
,TC;{ $O5
public static void log(int sMsg) x8#ODuH
{ SAv<&
System.err.println(sMsg); +Ezgn/bS&
} =P77"Dd
} TYgQJW?
j) vlM+
u:gtOjk2
/* e]>ori 8
**TestMethod.java h5zVGr
*/ t!;/Z6\Pb
package NetFox; y}2F9=
-7]Xjb5
)9nElb2
public class TestMethod { YE+$H%Jl!
# '|'r+
9ptFG]lZ
public TestMethod() L;t)c
{ ///xx/weblogic60b2_win.exe sKaE-sbJY
try{ #VbVsl
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); T3&`<%,f
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); /\d$/~BFi
SiteFileFetch fileFetch = new SiteFileFetch(bean); UHO_Z
fileFetch.start(); ]gb=
} xyHejE}
catch(Exception e){e.printStackTrace ();} ;&;W T
T~8 .9g
t2{~bzq1X
} /uqu32;o
i, nD5@#
]rBM5~
public static void main(String[] args) VDEv>u4
{ } /^C|iS7
new TestMethod(); q" @
} `cB_.&
} 748CD{KxW
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