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)); AR c
} C|]Zpn#{K
for(int i=0;i<nEndPos.length-1;i++) ?gCP"~
{ B^.:dn
nEndPos = nStartPos[i+1]; d"S\j@
} # S0N`V
nEndPos[nEndPos.length-1] = nFileLength; :0p$r pJP
} 1";s#Jq
} ]'Gz~Z%>F
[@NW
D8`SI21P
//启动子线程 0CI\Yd=
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; .f|)od[
for(int i=0;i<nStartPos.length;i++) k<RaC=
{ KK4rVb:-
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), \)W Z D
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), cDz^jC
nStartPos,nEndPos,i); rpEN\S%7P
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); &&C'\,ZK5
fileSplitterFetch.start(); @2 SL$0!QA
} %'dsb7n
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), G""=`@
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); VF9-&HuC
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", td2bL4
nEndPos = " + nFileLength); ,q Bu5t
// fileSplitterFetch[nPos.length-1].start(); yn{U/+
' @j8tK
Oin:5K)4-
//等待子线程结束 r}t%DH
//int count = 0; 23`pog{n
//是否结束while循环 Js!Zk\O
boolean breakWhile = false; Pu!%sGjD
;'|t>'0_
glWa?#1
while(!bStop) v=+>ids
{ *\[GfTL
write_nPos(); OH~I+=}.
Utility.sleep(500); m*TJ@gI*t
breakWhile = true; k12mxR/
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for(int i=0;i<nStartPos.length;i++) ?s: 2~Qlu
{ |7G=f9V
if(!fileSplitterFetch.bDownOver) "gi 1{
{ 5LxzET"P
breakWhile = false; cUr'mb
break; ]F,v#6qi
} LD}ZuCp!
} O.P:~
if(breakWhile) LpSd/_^b
break; <' b%
u|E9X[%
[Uu!:SZ
//count++; *:V"C\`^n
//if(count>4) aAkO>X%[
// siteStop(); 1He'\/#
} RIxGwMi%
@Tf5YZ*
XZ&q5]PJI
System.err.println("文件下载结束！"); zDofe*
} ;+]GyDgVq
catch(Exception e){e.printStackTrace ();} JxLD}$I
} Nc:>]
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9#niMv9
//获得文件长度 (g]J hG
public long getFileSize() uEkUK|
{ gkNvvuQXc
int nFileLength = -1; $+ ?A[{JG
try{ }\!38{&
URL url = new URL(siteInfoBean.getSSiteURL()); C$$lJ=>
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); [z`m`9Aq
httpConnection.setRequestProperty("User-Agent","NetFox"); }c*6|B@f
vc(6lN9>
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int responseCode=httpConnection.getResponseCode(); b7bbrR8
if(responseCode>=400) N{6Lvq[8
{ Y>[u(q&09O
processErrorCode(responseCode); AW:WDNQh8n
return -2; //-2 represent access is error mEe JK3D[
} R%N&Y~zH
d.uJ}=|
O hcPlr
String sHeader; geu8$^
bI~(<-S~K
O486:tF
for(int i=1;;i++) Af>Ho"i
{ `$D2w|
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); X6]eQ PN2
//Utility.log(in.readLine()); gyW##M@{
sHeader=httpConnection.getHeaderFieldKey(i); n/5)}( }K
if(sHeader!=null) HLcK d`$/
{ &Q"Ox{~W
if(sHeader.equals("Content-Length")) '\X<+Sm'
{ ef=LPCi?
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); VZ8HnNAbX
break; Ni[2 p
} s9Aq-N
} YS5Pt)?
else 29E9ZjSK
break; Iz\IQa
} PO[ AP%;
} M[R\URu8
catch(IOException e){e.printStackTrace ();} !fcr3x|Y~M
catch(Exception e){e.printStackTrace ();} 1[vmK,N=E
%vO b"K$X
w%[`'_[
Utility.log(nFileLength); T7=~l)I
agFWye
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return nFileLength; L.z`>1
} ,#42ebGHR
~cSOni`
s:y=X$&M
//保存下载信息（文件指针位置） f|1GlUA{t
private void write_nPos() Svo gvn
{ u;Q'xuo3
try{ b;O|-2AR
output = new DataOutputStream(new FileOutputStream(tmpFile)); nx >PZb
output.writeInt(nStartPos.length); +SSF=]4+
for(int i=0;i<nStartPos.length;i++) Y|=/*?o}
{ tF<|Eja*
// output.writeLong(nPos); q|. X[~e|
output.writeLong(fileSplitterFetch.nStartPos); FU|c[u|z
output.writeLong(fileSplitterFetch.nEndPos); `UpZk?k
} {g *kr1JM
output.close(); ~',<7eW
} W|@/<K$V
catch(IOException e){e.printStackTrace ();} {Ah\-{]
catch(Exception e){e.printStackTrace ();} r~uWr'}a}
} GyOo$FW
Cu0N/hBT
3!0Eh8ncI
//读取保存的下载信息（文件指针位置） F~dq7AS
private void read_nPos() ~)#JwY
{ gNO<`9q
try{ 0FFx
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Oi=>Usd
int nCount = input.readInt(); YN ~7nOw
nStartPos = new long[nCount]; k4+F
nEndPos = new long[nCount]; >*v^E9Y
for(int i=0;i<nStartPos.length;i++) m1X0stFRs"
{ H1'`* }V
nStartPos = input.readLong(); ~bCn%r2
nEndPos = input.readLong(); L "L@4B
} zhI} p.
input.close(); 3n/U4fn_
} 2!/_Xh
catch(IOException e){e.printStackTrace ();} ;9pOtr
catch(Exception e){e.printStackTrace ();} ~B%=g)w
} VrA9}"1x~*
\ qc8;"@
33_YZOy^j
private void processErrorCode(int nErrorCode) 6<+R55
{ Oc;0*v[I
System.err.println("Error Code : " + nErrorCode); /YWoDHL
} h*f=
-bK#&o,
h:3`e`J<h
//停止文件下载 HPAd@5d(
public void siteStop() ) w.cCDL c
{ N?H;fK4v
bStop = true; /I3#WUc;![
for(int i=0;i<nStartPos.length;i++) kn_%'7
fileSplitterFetch.splitterStop(); m-lUgx7
Cyxt EzPp
1o7 pMp=
} #e0tT+
} !6ZkLE[XJ<
//负责部分文件的抓取 3VbQDPG
**FileSplitterFetch.java ip4:px-
*/ C26PQGo#$
package NetFox; ^.F@yo2}
g83!il\
]BU,*YaB
import java.io.*; AG2iLictv
import java.net.*; ,qak_bP
&E$jAqc
d{@X-4k:
public class FileSplitterFetch extends Thread { `!HGM>
LMWcF'l
9}Tf9>qP>M
String sURL; //File URL '2a}1?
long nStartPos; //File Snippet Start Position o_p//S#q
long nEndPos; //File Snippet End Position qn#\ro1H
int nThreadID; //Thread's ID _JA.~edqM
boolean bDownOver = false; //Downing is over \Nu(+G?e
boolean bStop = false; //Stop identical gM20n^
FileAccessI fileAccessI = null; //File Access interface 2As 4}
W|3XD-v@
qtTys gv
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException '8~7Ru\KyX
{ . zvF!!z
this.sURL = sURL; Pv{ {zyc
this.nStartPos = nStart; =*qu:f\y
this.nEndPos = nEnd; 6#On .Q
nThreadID = id; ="RDcf/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 Dg/&m*Yl
} L@w|2
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A"k6n\!n;
public void run() Aj.TX%}`h
{ nI%0u<=d
while(nStartPos < nEndPos && !bStop) ;Br8\2=$
{ kssS,Ogf\_
zv!%u=49
:k075Zr/#D
try{ y@'8vOh`
URL url = new URL(sURL); {IJV(%E
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); +/7UM x1
httpConnection.setRequestProperty("User-Agent","NetFox"); {%@zQ|OO0
String sProperty = "bytes="+nStartPos+"-"; ZPn`.Qc
httpConnection.setRequestProperty("RANGE",sProperty); 8Vv"'CU#
Utility.log(sProperty); H=z@!rJc.
bV&/)eqv
m,$oV?y>j
InputStream input = httpConnection.getInputStream(); uh%%MhTjv
//logResponseHead(httpConnection); (1fE^KF@f
|&3m'"(
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byte[] b = new byte[1024]; m;lwMrY\7>
int nRead; TS)p2#
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) Vp\BNq_!s
{ D|,d_W
nStartPos += fileAccessI.write(b,0,nRead); V{@<Z8sW#
//if(nThreadID == 1) xZjD(e'
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); |Rw0$he
} C 7YZ;{t
tQbDP!,A*=
?C//UN;
Utility.log("Thread " + nThreadID + " is over!"); Y.3]vno?X
bDownOver = true; ~!&WK,k6
//nPos = fileAccessI.write (b,0,nRead); ]]Ypi=<'
} aG8}R~wH&
catch(Exception e){e.printStackTrace ();} 3Tg
} 6gJy<a3
} @3c5"
]nhLv!Co
"wmQ,=
//打印回应的头信息 41mg:xW(J
public void logResponseHead(HttpURLConnection con) b[?6/#N
{ /d9I2~}B
for(int i=1;;i++) kWc%u-_
{ !v<r=u
String header=con.getHeaderFieldKey(i); )?joF)
if(header!=null) <w(UDZ
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ;#P@(ZVT
Utility.log(header+" : "+con.getHeaderField(header)); a Umcs!@
else AtYe\_9$C
break; EE#4,d`J
} gfw,S;
} dY68wW>d|
"3LOL/7f
Xz4!#,z/
public void splitterStop() 1`r 4
{ [Pi8gj*
bStop = true; W`^'hka
} bv5,Yk
;&37mO/T
2)h i(
} 49^;T;'v
#+|{l*>
!>Db
/* SfyZ,0
**FileAccess.java )TFaG[tj
*//文件访问(定位，写) 2PE|4zG
package NetFox; 'W3>lAPx!
import java.io.*; _)O1v%]"4
9xyj,;P>
! pR&&uG
public class FileAccessI implements Serializable{ {=PO`1H
)&+j#:
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 UGj!I
RandomAccessFile oSavedFile; }|%dN*',
long nPos; [94A?pn[z
;U<;R
Q}d6+C
public FileAccessI() throws IOException $Lv,e\]
{ 7f#e#_sM;
this("",0); fQ=Yf?b
} E#v}//
z4b2t}
w<<>XIL
public FileAccessI(String sName,long nPos) throws IOException n'9Wl'
{ )~v`dwKj;
oSavedFile = new RandomAccessFile(sName,"rw"); 57*z0<
this.nPos = nPos; #Gx%PQ`
oSavedFile.seek(nPos); QxH%4 )?
} R22YKXU
7/a[;`i*!
d }=fJ
public synchronized int write(byte[] b,int nStart,int nLen) *%7[{Loz
{ gPh;
int n = -1; *9y)B|P^
try{ #wK {G)J
oSavedFile.write(b,nStart,nLen); vP`Sz}FU
n = nLen; a$yAF4HR<
} q.U` mtS
catch(IOException e) s]50Y-C
{ -;20|US)u
e.printStackTrace (); ? [l[y$9
} 6X~.J4
z85%2Apd
x2=Bu#Y
return n; }pdn-#
} H<#M)8
8om6wALXB
7n9&@D3:P
} ,dhJ\cQ~
L15?\|':Y
nICc}U?k
/* B>rz<bPT
**SiteInfoBean.java <k!M+}a 9V
*/ #<s6L"Z-
package NetFox; 2-728
ukpbx;O:hc
[Ul"I-K
public class SiteInfoBean { HC(Vu
C-E~z{
)'+" y~
private String sSiteURL; //Site's URL 83K)j"!<X
private String sFilePath; //Saved File's Path ]$Pl[Vegy
private String sFileName; //Saved File's Name x? tC2L
private int nSplitter; //Count of Splited Downloading File 1DgRV7
WvR-0>E
\(2w/~
public SiteInfoBean() (hNTr(z
{//nSplitter的缺省值为5 `qnp
//default value of nSplitter is 5 {L~j;p_G&
this("","","",5); +wc8rE6+W
} 0gO_dyB
mivb}cKM
rV84?75(Y
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) <}t~^E,
{ 7'Z-VO
sSiteURL= sURL; YbtsJ <w
sFilePath = sPath; g xY6M4
sFileName = sName; 3}dTbr4y
this.nSplitter = nSpiltter; J{;XNf =
k-IL%+U
p[R4!if2
} Q,R>dkS
(VDY]Q)
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public String getSSiteURL() :No`+X[Kq
{ 2(LF @xb
return sSiteURL; ~hD!{([
} n2}(Pt.
>*s_)IH2
EP,j+^RVf
public void setSSiteURL(String value) X3e&c
{ 2[~|#0x
sSiteURL = value; W*S}^6ZT`
} "| Oj!&0
_PT5
?M!Mb-C[
public String getSFilePath() 94^)Ar~O
{ JguPXHa0
return sFilePath; 9gq+,g>E_
} J,4,#2M8
QO2@K1Y
(xpt_]Q!H
public void setSFilePath(String value) J^<Gi/:*^
{ Drm#z05i[g
sFilePath = value; RO+ jVY~H-
} YTpiOPf
PAng(tubl
8tfM,.]_i
public String getSFileName() '41'Gn
{ .3 >"qv
return sFileName; GuK3EM*_
} P5Lb)9_Jw
Zt_~Zxn3
(4o<U%3kGq
public void setSFileName(String value) &!P' M
{ X*cDn.(I
sFileName = value; H9;0$Y(e-
} ;~D$rT
yFoPCA86y
$%BI8_
public int getNSplitter() U!d|5W.{Q
{ zh{,.c
return nSplitter; {wy{L-X
} U#V&=~-
cWtuI(.
/!Ay12lKE}
public void setNSplitter(int nCount) i<0_sxfUD
{ m)7Ql!l
nSplitter = nCount; vB74r]'F
} r>: ~!o*
} y1{TVpN
>``sM=Wat
BG|m5f
/* \?v?%}x
**Utility.java W4;/;[/L
*/ GCf,Gfmr
package NetFox; vA3wn><
BP4xXdG
@C-03`JWuK
public class Utility { NSawD.9mV
pfBe24q
rjffpU
public Utility() nw4I<Q
{ BLN|QaZ
3Fb9\2<H
lArKfs/
} +7\d78U
'-U&S
//线程睡眠 ]p8zT|bv
public static void sleep(int nSecond) * N]^(+/A
{ .k:heN2-x
try{ ">._&8KkE0
Thread.sleep(nSecond); !4-4i
} X+1Mv
catch(Exception e) d-3.7nJ:
{ /#WvC;B
e.printStackTrace (); V7b;qC'
} Rk,'ujc
} beaSvhPU
%afN&T
//日志 hkb&]XWi[
public static void log(String sMsg) 9tX+n{i
{ Zg$S% 1(Q
System.err.println(sMsg); i;rcgd
} H;R~d%!b
6hMKAk
#f [}a
public static void log(int sMsg) t"zi'9$t
{ e)= "Fq!
System.err.println(sMsg); ZNVrja*
} Sn S$5o
} z&cM8w:
SRtw
T|8:_4/l
/* SJ91(K
**TestMethod.java Q^;:Kl.b
*/ ua"2nVxK_K
package NetFox; s+~GQcj<T
)=#e*1!b
Esu{c9,
public class TestMethod { 2eHVl.C5
qu1+.z=|
=z;]FauR!
public TestMethod() RL:B.Lv/W
{ ///xx/weblogic60b2_win.exe O6/:J#X%
try{ NVghkd
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); CY*o"@-o5)
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); $*VZa3B\
SiteFileFetch fileFetch = new SiteFileFetch(bean); 06O_!"GD}
fileFetch.start(); |h}4J
} "u]&~$
catch(Exception e){e.printStackTrace ();} GeDI\-
C{,^4Eh3r
:hT.L3n,
} e!PB3I
%ufh
"={*0P
public static void main(String[] args) F^$;hMh%
{ n$N$OFuO
new TestMethod(); {nXygg J
} Cdy,8*
} O/|))H?C
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