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)); Zotz?jVVr
} ;U |NmC+
for(int i=0;i<nEndPos.length-1;i++) iDZrK%fl
{ 0[.3Es:_
nEndPos = nStartPos[i+1]; W3^.5I
} |,3l`o k
nEndPos[nEndPos.length-1] = nFileLength; 7krh4
} EY]a6@;
} :JR<SFjm
Lj4&_b9
u2 7S%2P
//启动子线程 Z+0?yQ=%
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; jM*AL X
for(int i=0;i<nStartPos.length;i++) |Td_S|:d
{ 4KE)g
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), UIn^_}jF`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), ?gLAWz
nStartPos,nEndPos,i); =qw&dwIQ
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); S9J5(lYv~N
fileSplitterFetch.start(); =:4?>2)
} N*f^Z#B]
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), Rxx>{+f4M
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); L.kD,'G}>
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", yOc|*O=]U
nEndPos = " + nFileLength); Fqo&3+J4
// fileSplitterFetch[nPos.length-1].start(); J2'K?|,m
QskUdzQ=
NS Np
//等待子线程结束 >=Jsv
//int count = 0; prUHjS
//是否结束while循环 85} ii{S
boolean breakWhile = false; Bq *[c=(2
Q? qjWZY
xo(k?+P>.
while(!bStop) l2(.>-#
{ dN<5JQql
write_nPos(); wk@yTTnb
Utility.sleep(500); ;|6FdU
breakWhile = true; 2hy NVG&$
sYW[O"oNi
}C_|gd
for(int i=0;i<nStartPos.length;i++) FRgLlp8x
{ {EL'd!v7e
if(!fileSplitterFetch.bDownOver) v~}5u 5$O
{ YwXXXh
breakWhile = false; N#UXP5C(
break; %[XY67A3I
} ?I\v0H*
} GQ<Ds{exs>
if(breakWhile) Y#`Lcg+r,
break; awFhz 6
9k}<Fz"^.
dgslUg9z3g
//count++; x<@kjfm5
//if(count>4) HVGr-/
// siteStop(); 0Z,{s158L
} O~6Q;qP
.uKx>YB}
7WP%J-
System.err.println("文件下载结束！"); g#qNHR
} P_}/#N{C
catch(Exception e){e.printStackTrace ();} q`[K3p
} {y b D
q3)wr%!k5D
]H+{eJB7O
//获得文件长度 \B&6TeR
public long getFileSize() Xem5@ (u
{ e/>:K' {
int nFileLength = -1; qOi5WX6F/
try{ XVF^,Yf
URL url = new URL(siteInfoBean.getSSiteURL()); f^?uY8<
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ;E#\
httpConnection.setRequestProperty("User-Agent","NetFox"); \TUE<<?1s
?+Q$#pb
sB6dpD
int responseCode=httpConnection.getResponseCode(); #k9<
if(responseCode>=400) +#s;yc#=2
{ \?&Au
processErrorCode(responseCode); D%U:!|G
return -2; //-2 represent access is error YjLe(+WQ
} -\Z `z}D
/EU; ?O
.=XD)>$
String sHeader; l{5O5%\,
4\6:\
LwOJ|jA(,
for(int i=1;;i++) > :Ze4}(
{ i3PKqlp.
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); jo_ sAb
//Utility.log(in.readLine()); E:w:4[neh
sHeader=httpConnection.getHeaderFieldKey(i); g~!$i`_b
if(sHeader!=null) P"F{=\V1`<
{ jV^C19
if(sHeader.equals("Content-Length")) Q]rqD83((
{ ,H39V+Y*
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); [(|v`qMv/g
break; !5UfWk\G
} }lP5GT2
} 9P.(^SD][z
else RqLNp?V%
break; HabzCH
} @Tr&`Hi
} 2]2H++
catch(IOException e){e.printStackTrace ();} <GF@L
catch(Exception e){e.printStackTrace ();} #6W,6(#^#
Jq .L:>x
*Hs*,}MS
Utility.log(nFileLength); eg3L:rk_
2+'|kt2
w!`Umll2
return nFileLength; iYKU[UP?
} `*yAiv>
U-EhPAB@
"K?Q
//保存下载信息（文件指针位置） ,w2WS\`%
private void write_nPos() b/<mRQ{
{ 2\0Oji\6
try{ (A{NF(
output = new DataOutputStream(new FileOutputStream(tmpFile)); r5 yO5W
output.writeInt(nStartPos.length); =& -[TPW
for(int i=0;i<nStartPos.length;i++) OOB^gf}$'
{ zZ=$O-&%
// output.writeLong(nPos); T'1gy}
output.writeLong(fileSplitterFetch.nStartPos); `FJ|W6%
output.writeLong(fileSplitterFetch.nEndPos); RUGv8"j
} aFY u}kl
output.close(); 7>n"}8i
} J :S'uxM
catch(IOException e){e.printStackTrace ();} <m-.aK{9
catch(Exception e){e.printStackTrace ();} Y"!uU.=xJ
} 7petHi
ll<mE,
|0 !I5|<k
//读取保存的下载信息（文件指针位置） zOGR+Gq_Z
private void read_nPos() m^I,}1H4
{ \c7>:DH
try{ ?`AGF%zp
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); ."mlSW"Wm
int nCount = input.readInt(); 5v9Vk`3'
nStartPos = new long[nCount]; 4:1)~z
nEndPos = new long[nCount]; Mo^`\/x!
for(int i=0;i<nStartPos.length;i++) 2 9#]Vr
{ kNPDm6m
nStartPos = input.readLong(); Z]vL%Gg*!
nEndPos = input.readLong(); QCpM|,drS
} 3t(c_:[%
input.close(); V1<`%=%_W
} +a$|Sc
catch(IOException e){e.printStackTrace ();} X:=c5*0e
catch(Exception e){e.printStackTrace ();} ut&/\k=N
} 6 h'&6
"&QH6B1U6H
c2<,|D|
private void processErrorCode(int nErrorCode) o\6iq
{ L"vj0@n'0
System.err.println("Error Code : " + nErrorCode); SW9fE:v
} <1@ (ioPH
GGnp Pp
(V?@?25
//停止文件下载 v0@)t&O
public void siteStop() w sY}JT
{ @Zm Jz
bStop = true; `ZGcgO<c\
for(int i=0;i<nStartPos.length;i++) 4tJa-7
fileSplitterFetch.splitterStop(); ,W*H6fw+
1 Z[f {T)
9B/1*+ M
} Gvx[8I
} ^Mytp>7
//负责部分文件的抓取 *Km7U-BG
**FileSplitterFetch.java w>979g
*/ YV([2
package NetFox; 8_Z/o5s
6E^~n
`w<J25
import java.io.*; QUOKThY?
import java.net.*; \dkOK`)b
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public class FileSplitterFetch extends Thread { CAgaEJhX3
0=![fjm
8MZ$T3IM
String sURL; //File URL (lWq[0^N
long nStartPos; //File Snippet Start Position g}Qx`65:
long nEndPos; //File Snippet End Position 4~|<`vqN
int nThreadID; //Thread's ID ycX{NDGs
boolean bDownOver = false; //Downing is over ngyY
boolean bStop = false; //Stop identical %l$W*.j|;
FileAccessI fileAccessI = null; //File Access interface !ALZBB.r(
p;%<mUI
Ceg!w#8Z,
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException J?Iq9f
{ L`3n2DEBf
this.sURL = sURL; ;BBpN`T
this.nStartPos = nStart; lG"H4Aa>
this.nEndPos = nEnd; g.C5r]=+&
nThreadID = id; }5bM1h#z
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Jqfm@Y
} u#jC#u^M
+)/Uu3"=
{#hVD4$b
public void run() 1"]P`SY$r
{ wahZK~,EaY
while(nStartPos < nEndPos && !bStop) YQVcECj
{ K=\&+at1
?[TW<Yx
8^ #mvHah
try{ DTY<0Q.
URL url = new URL(sURL); FvXqggfGv
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); j _ ;fWBD:
httpConnection.setRequestProperty("User-Agent","NetFox"); z<n-Gzwk
String sProperty = "bytes="+nStartPos+"-"; tXq)nfGe{
httpConnection.setRequestProperty("RANGE",sProperty); !OE*z $\
Utility.log(sProperty); FPv"N'/
l(:kfR~AC
)=_ycf^MC
InputStream input = httpConnection.getInputStream(); Y&f\VNlT
//logResponseHead(httpConnection); #`ejU&!6
:zp`6l
"H+,E_&(
byte[] b = new byte[1024]; .v])S}K
int nRead; _\zQ"y|G
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) {fz$Z!8-
{ `W5-.Tv
nStartPos += fileAccessI.write(b,0,nRead); h;M3yTM-
//if(nThreadID == 1) IeTdN_8
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); jw>hk
} @d&H]5
r9@AT(
?R'Y?b
Utility.log("Thread " + nThreadID + " is over!"); # cFr
bDownOver = true; TFH&(_b
//nPos = fileAccessI.write (b,0,nRead); +5X DF
} <z0WLw0'z
catch(Exception e){e.printStackTrace ();} q7Es$zjX
} _vl}*/=Hc
} 4JMiyiW&
X0uJNHO
yyP-=Lhmo=
//打印回应的头信息 iRw&49
public void logResponseHead(HttpURLConnection con) };katqzEg
{ x;#zs64f
for(int i=1;;i++) ;y1Q6eN
{ =8JB8ZFP
String header=con.getHeaderFieldKey(i); p2 !FcFi
if(header!=null) O)#U ^
//responseHeaders.put(header,httpConnection.getHeaderField(header)); jRQ+2@n{E
Utility.log(header+" : "+con.getHeaderField(header)); mTf<
else 9M-K]0S(
break; %oof}=MxCL
} mP^SS Je
} Pe ~c
0(\+-<
?IW_O~Js
public void splitterStop() pJ^NA2
{ 6X_\Ve
bStop = true; PHra+NY#A
} AEg(m<t
SvuTc!$?
EX "|H.(
} ,YLF+^w-
P+(i^=S
wL{qD
/* Xs$Ufi
**FileAccess.java j8$Zv%Ca%
*//文件访问(定位，写) @;^Y7po6u
package NetFox; cxP&^,~
import java.io.*; r4{<Z3*N
2F+gF~znQ
w*!wQ,o
public class FileAccessI implements Serializable{ ALT^8c&K
nCnjq=
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 )D@~|j:
RandomAccessFile oSavedFile; E^V|
long nPos; 6|;Uq'
?6N3tk-2
$yb@ Hhx>
public FileAccessI() throws IOException !xK=#pa
{ eSy(~Y
this("",0); J"CJYuGW,
} <"tDAx
"@ E3MTW
!@L=;1,
public FileAccessI(String sName,long nPos) throws IOException {qpi?oY
{ .#w6%c@
oSavedFile = new RandomAccessFile(sName,"rw"); (Tvcq
this.nPos = nPos; 7+,vTsCd
oSavedFile.seek(nPos); -n))*.V
} c:hK$C)T
Gt-UJ-RR y
$:bih4@>
public synchronized int write(byte[] b,int nStart,int nLen) a)s;dp}T%
{ 9;=dxWf
int n = -1; eph)=F$
try{ Zq"7,z7
oSavedFile.write(b,nStart,nLen); EU+cca|qS9
n = nLen; M0'v&g
} `DW2spd
catch(IOException e) B#l?IB~
{ = !2NU
e.printStackTrace (); QwWW!8
} &0 \ ci9o
Ngy=!g?Hk=
~}ovuf=%
return n; m,MSMw1p
} lxb zHlX
I9 64
fg*@<'
} OI/@3"L{
2YBIWR8z
'\7G@g?UZ
/* tY/vL^mi
**SiteInfoBean.java +pmu2}E.3
*/ Oe!6){OG)
package NetFox; L'A)6^d@S
_M5%V>HO
HEF?mD3h
public class SiteInfoBean { ^4>k%d
X9=N%GY[
K 1#ji*Tp
private String sSiteURL; //Site's URL Tx>K:`oB
private String sFilePath; //Saved File's Path EtJ8^[u2J
private String sFileName; //Saved File's Name Ao.\
private int nSplitter; //Count of Splited Downloading File 963aW*r
<z)m%*lvU
g.DLfwI|
public SiteInfoBean() z~oDWANP
{//nSplitter的缺省值为5 4gBp8*2
//default value of nSplitter is 5 >)nS2bOE
this("","","",5); t;q7t!sC]
} TJ_=1Y@z
X`r*ob
:}}%#/nd
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) iz^qR={bW
{ |(R5e
sSiteURL= sURL; Zj9c9
sFilePath = sPath; C*kK)6v`
sFileName = sName; Kuw^qX"
this.nSplitter = nSpiltter; C"V%# K
[3>GGX[Ic
[0;buVU.
} 6z,Dyy]tl
GF<[}
V2d,ksKwn
public String getSSiteURL() m@G i6
{ +Wn&,?3^
return sSiteURL; %:9oDK
} DC4C$AyW r
^4Uw8-/9
&l2TeC@;
public void setSSiteURL(String value) .TB"eUy
{ \_]En43mg
sSiteURL = value; H=c`&N7E
} L=!of{4Z(}
NTs7KSgZ
vp)Vb^K>
public String getSFilePath() Gwec4D
{ Z=z%$l
return sFilePath; J>0b1
} 9q[;u[A8^
W[''Cc.
!7p}C-RZp
public void setSFilePath(String value) 2b@tj 5
{ z}4L=KR\v
sFilePath = value; wTq{sW&
} m\u26`M
Xz{~3ih
7:=k`yS,
public String getSFileName() R[[ ,q:4
{ m]Y;c_DO:
return sFileName; M!m?#xz'c
} t;qP']2
X"asfA[6K
},-*
public void setSFileName(String value) Tenf:Hm/k
{ cWAtju?L;
sFileName = value; {=:#S+^ER
} fL*T3[d
&p(0K4:
wVl+]zB
public int getNSplitter() GC@+V|u
{ =6 r:A<F!n
return nSplitter; 7N8H)X
} J1ON,&[J
BzJ;%ywS
A&5:ATQ/|
public void setNSplitter(int nCount) 5N7H{vT_
{ D/(CU#i"
nSplitter = nCount; *#U+qgA;`
} _c(4o:
} f{#j6wZM
Gctsp2ndW
|9K<-yD
/* W m&
**Utility.java "j<bA8$Vw
*/ ,yMU@Vg
package NetFox; +JyUe
k\r(=cex6
?knYY>Kzh1
public class Utility { /*)Tl
%D}H|*IPu
=^DLywAh}u
public Utility() G'z{b$?/[
{ =<z.mzqu5
{r85l\u)Q\
v}JD2.O+
} yzsab ^]
K{fsn4rk
//线程睡眠 LaMLv<)k
public static void sleep(int nSecond) !]` #JAL7
{ VaONd0Z I
try{ zy'D!db`Z
Thread.sleep(nSecond); &}6KPA;
} ksR1kvTm
catch(Exception e) eet Q}]
{ Q4*-wF-P
e.printStackTrace (); (7FW9X;
} LtgXShp_!
} ,,L2(N
VR{+f7:}
//日志 oFsM6+\/S
public static void log(String sMsg) tiPa6tQ
{ M\<w#wZ
System.err.println(sMsg); H].y w9
} $(pF;_W
; 0v>Rfa
m} ?rJ
public static void log(int sMsg) `Nh"
{ %qf V+^
System.err.println(sMsg); ef!XV7P
} ~X(UcZ2
} ,"0)6=AE
>gll-&;t
nz.{P@[Qk
/* ^D^JzEy'?C
**TestMethod.java revF;l6->C
*/ %^.%OCX:
package NetFox; yL4 T
|R/.r_x,V?
d)o!5L
public class TestMethod { Ck =;1sGh
B$Z3+$hfF
P,DC7\
public TestMethod() T'-FV
{ ///xx/weblogic60b2_win.exe "t=hzn"~%
try{ Joe_PS
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); :G w~7v_
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); `Pn[tuIO
SiteFileFetch fileFetch = new SiteFileFetch(bean); U:6W+p8
fileFetch.start(); 5+Mdh`
} \VMD$zZx
catch(Exception e){e.printStackTrace ();} Ty(@+M~-
4674SzL
)jrT6x^IB
} t+r:"bb
va|*c22;|
Q?t^@
public static void main(String[] args) 2I1uX&g
{ rZPT89M6
new TestMethod(); N/QiI.V6
} LK9g0_
} $4FX(O0Q@
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