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)); _0rHxh7}q
} $VrKoL\ScA
for(int i=0;i<nEndPos.length-1;i++) 28j=q-9Z
{ `37GVo4
nEndPos = nStartPos[i+1]; | 3`qT#p{
} ?]=fC{Rh
nEndPos[nEndPos.length-1] = nFileLength; lK? Z38
} / h6(!-"
} Y"uFlHN&i
Jb~-)n2
Dk'EKT-
//启动子线程 xmDX1sL**
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Ohm>^N;
for(int i=0;i<nStartPos.length;i++) >q&Q4E0
{ =oF6|\]{;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ZHshg`I`
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Te8BFcJG
nStartPos,nEndPos,i); id-VoHdK
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); !j(KbAhWZ
fileSplitterFetch.start(); MGO.dRy_
} c#G]3vTdE
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), n(Up?_
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); $l&&y?()
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", ~?}/L'q!b
nEndPos = " + nFileLength); }eX_p6bBw
// fileSplitterFetch[nPos.length-1].start(); X*~NE\
!40t:+I
v`hv5wQ
//等待子线程结束 ] %*970
//int count = 0; H&L=WF+x
//是否结束while循环 vtFA#})~
boolean breakWhile = false; oT5xe[{yj
#^Dc:1,
SPV'0* Z
while(!bStop) j8os6I
{ 3D~Fu8Hg1
write_nPos(); '3o0J\cz
Utility.sleep(500); B-[SUmHr
breakWhile = true; s\&_Kbw]c
W4CI=94
$/C<^}A
for(int i=0;i<nStartPos.length;i++) oQDOwM,
{ JLAg-j2
if(!fileSplitterFetch.bDownOver) #{0DpSzE5
{ c 3@SgfKmk
breakWhile = false; Vk_*]wU
break; ^c]Sl
} L\og`L)5\
} ZZC= 7FB
if(breakWhile) dW7dMx
break; 1A-8,)
Hcd>\0
+29;T0>a
//count++; T , =ga
//if(count>4) Za!c=(5
// siteStop(); DuvP3(K
} ud:?~?j&w
U30)r+&
V8Q#%#)FHe
System.err.println("文件下载结束！"); 5?kA)!|UB
} 8{+~3@T
catch(Exception e){e.printStackTrace ();} @sKAsn
} 16N8h]l
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73~Mq7~8
//获得文件长度 |->y'V
public long getFileSize() UKK}$B
{ &SN$D5U'
int nFileLength = -1; (P#2Am$
try{ i`]M2Q
URL url = new URL(siteInfoBean.getSSiteURL()); ,:\2Lf
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); na']{a1K
httpConnection.setRequestProperty("User-Agent","NetFox"); ;(0:6P8I
k7{fkl9|#
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int responseCode=httpConnection.getResponseCode(); *gz{:}NX
if(responseCode>=400) xN"KSQpu
{ \Di~DN1
processErrorCode(responseCode); <vt^=QA'
return -2; //-2 represent access is error )dL?B9d:
} rF0zGNH
($(1KE
*vAOUqX`x
String sHeader; e3>Re![_.
-N\{QX1Yd
nv$
for(int i=1;;i++) )Elr8XLw
{ L7Oytdc<
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); /#G"'U/
//Utility.log(in.readLine()); {t/!a0\HS
sHeader=httpConnection.getHeaderFieldKey(i); >qF KXzI
if(sHeader!=null) vWkKNB
{ [!R%yD;
if(sHeader.equals("Content-Length")) wCt+{Y3T
{ LVEVCpp@
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); <$yer)_J!k
break; ,IJNuu\
} .hJ8K#r
} _SP u`=~K
else d7^XP
break; 8e\v5K9
} ABHZ)OM
} CLkVe
catch(IOException e){e.printStackTrace ();} 0KQ8;&a|
catch(Exception e){e.printStackTrace ();} rbtV,Y
4P~<_]yf
\~)573'
Utility.log(nFileLength); GO)rpk9
BkZ%0rw%
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return nFileLength; 'j)eqoj
} D1Sl+NOV
'j3'n0o
P~qVr#eU
//保存下载信息（文件指针位置） &"kx(B
private void write_nPos() &V:dcJ^Q
{ ]czy8n$+
try{ )[K3p{4
output = new DataOutputStream(new FileOutputStream(tmpFile)); ;&!dD6N
output.writeInt(nStartPos.length); #] GM#.
for(int i=0;i<nStartPos.length;i++) UKJY.W!w4
{ rODKM-7+
// output.writeLong(nPos); \fKE~61
output.writeLong(fileSplitterFetch.nStartPos); `P5"5N\h
output.writeLong(fileSplitterFetch.nEndPos); ZkIQ-;wx
} LuqaGy}>-
output.close(); .)3 2WD%
} {;}8Z$
catch(IOException e){e.printStackTrace ();} YQ)m?=+J
catch(Exception e){e.printStackTrace ();} i@J,u
} 8 KkpXaz
Vx*q'~4y!|
\;6F-0
//读取保存的下载信息（文件指针位置） &rd(q'Vi
private void read_nPos() I>5@s;
{ $ B9=v
try{ =@w:
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); xKr,XZu
int nCount = input.readInt(); `SwnKg
nStartPos = new long[nCount]; 0&\Aw'21
nEndPos = new long[nCount]; heKI<[8l
for(int i=0;i<nStartPos.length;i++) 2$o[
{ 0/ Ht;(
nStartPos = input.readLong(); 'oHR4O*
nEndPos = input.readLong(); (Lo2fY5
} 709eLhXrH
input.close(); ,![=_d
} mCGcM^21-x
catch(IOException e){e.printStackTrace ();} XJzXxhk2
catch(Exception e){e.printStackTrace ();} ".)_kt[
} %yMzgk[u
`-H:j:U{
?W n(ciO
private void processErrorCode(int nErrorCode) :65HMWy.
{ W*<]`U_.
System.err.println("Error Code : " + nErrorCode); <C$<(Dw5
} jyGVbno`
E%^28}dN
yx2.7h3
//停止文件下载 }SV3PdE
public void siteStop() 6\3k0z
{ [KH?5C
bStop = true; DOerSh_0W
for(int i=0;i<nStartPos.length;i++) S0+zq<
fileSplitterFetch.splitterStop(); upDQNG>d
C'._}\nX
iW?9oe
} 1,j9(m2
} QP B"EW
//负责部分文件的抓取 !T*B{+|
**FileSplitterFetch.java _")h %)f
*/ |&Pl4P
package NetFox; m=MT`-:
BB.TrQM.#
\Wc/kY3&
import java.io.*; >y9o&D
import java.net.*; \`zG`f
yU|ji?)e
uB1!*S1f
public class FileSplitterFetch extends Thread { fqb$_>3Ol
C.E>)
A7C+&I!L
String sURL; //File URL Fw9``{4w
long nStartPos; //File Snippet Start Position nEm7&Gb
long nEndPos; //File Snippet End Position =.E(p)fz
int nThreadID; //Thread's ID [bv@qBL
boolean bDownOver = false; //Downing is over 9@Sb! 9h
boolean bStop = false; //Stop identical &XRFX 5gP
FileAccessI fileAccessI = null; //File Access interface l~YNmmv_
3}21bL
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public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException q=Yerp3~
{ AfN
this.sURL = sURL; f^4*.~cB
this.nStartPos = nStart; d5y2Y/QO
this.nEndPos = nEnd; C[nr>
nThreadID = id; ? SP7vQ/
fileAccessI = new FileAccessI(sName,nStartPos);//定位 9Nu#&_2R
} |V\.[F2Fe
j dhml%pAd
#U52\3G
public void run() ]zU<=b@
{ Sqf.#}u<=
while(nStartPos < nEndPos && !bStop) K=x1mM+RK
{ IKDjatn
F[=lA"F^
E$tk1SVo
try{ +~Lzsh"
URL url = new URL(sURL); htYrv5q=M
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); -Y=c g;
httpConnection.setRequestProperty("User-Agent","NetFox"); d:pm|C|F
String sProperty = "bytes="+nStartPos+"-"; $pfe2(8
httpConnection.setRequestProperty("RANGE",sProperty); $Ds]\j*
Utility.log(sProperty); 8.Ef5-m
?gwbg*
6r=)V$K<
InputStream input = httpConnection.getInputStream(); %]0U60
//logResponseHead(httpConnection); &NjZD4m`=
b*F~%K^i$
~|{)h^]@
byte[] b = new byte[1024]; sLa)~To
int nRead; *rz(}(r
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) L*01l"5
{ l;}7A,u
nStartPos += fileAccessI.write(b,0,nRead); ,beR:60)
//if(nThreadID == 1) ,DuZMGg
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); s<_LcQbt{
} [RFK-E
M(zY[O
qb>r\bc
Utility.log("Thread " + nThreadID + " is over!"); DgT.Lku?
bDownOver = true; $;i$k2n:
//nPos = fileAccessI.write (b,0,nRead); 60%~+oHi~
} gDNTIOV
catch(Exception e){e.printStackTrace ();} P9i9<pR
} vDeG20.?Z
} sQ:VrXwP
y7)[cvB
hf^`at
//打印回应的头信息 FR,#s^kF
public void logResponseHead(HttpURLConnection con) k\&IFSp
{ <<On*#80w
for(int i=1;;i++) 0S:!Gv+
{ qVD!/;l
String header=con.getHeaderFieldKey(i); @VC9gdO/
if(header!=null) Qv0>Pf
//responseHeaders.put(header,httpConnection.getHeaderField(header)); @52=3
Utility.log(header+" : "+con.getHeaderField(header)); /N[o[q
else RQS:h]?:l
break; m)|.:sj
} ZYR,8y
} xDA,?i;T 0
ok%a|Zz+]
z?uQlm*We
public void splitterStop() aRO_,n9
{ @z$pPo0fW
bStop = true; D0y,TF
} `-K)K<
m wEVEx24
BRU9LS
} .`Old{<
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_ U8OIXN
/* 9Ajgfy>
**FileAccess.java _/%]:
*//文件访问(定位，写) FQ|LA[~
package NetFox; n?e@):
import java.io.*; o eJC
Z!RRe]"y
fyg~KF}
public class FileAccessI implements Serializable{ &pMlt7
snTJe[^d
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 IJ_'w[k
RandomAccessFile oSavedFile; Pvg
long nPos; Ro'4/{}+
OZC/+"\,
J!A/r<
public FileAccessI() throws IOException {F(-s"1;xO
{ Q9eYF-+
this("",0); m['v3m:
} jWv3O&+?X
yNqm]H3<MP
# McK46B z
public FileAccessI(String sName,long nPos) throws IOException 71L\t3fG
{ m.HX2(&\3
oSavedFile = new RandomAccessFile(sName,"rw"); -@ UN]K
this.nPos = nPos; k;K> ,$F
oSavedFile.seek(nPos); z%}CBTm
} ]cLEuE^&
~aqT~TL_
{? K|(C
public synchronized int write(byte[] b,int nStart,int nLen) D,GPn%Wqi
{ <r7qq$
int n = -1; e"o6C\c
try{ M\y~0uZ
oSavedFile.write(b,nStart,nLen); ?HEtrX,q
n = nLen; J:~[j
} p-Rm,xyL%
catch(IOException e) -VreBKn
{ 3lLW'g&=
e.printStackTrace (); XUQW;H
} oieQ2>lYh
~.4W,QLuD
u"#6_-0y
return n; o&hKg#nO83
} *3.yumcv{L
I!F}`d
,Ou1!`6?t
} A"\P&kqMV
f74%YY
~C/Yv&58
/* e_I; y
**SiteInfoBean.java 0uVk$\:i
*/ oRT
package NetFox; X ]pR,\B
)8x:x7?
.y %pGi
public class SiteInfoBean { y(/jTS/hd
Xc8= 2n
JK(`6qB>(6
private String sSiteURL; //Site's URL up+.@h{
private String sFilePath; //Saved File's Path ?dJ/)3I%F
private String sFileName; //Saved File's Name zt)p`kdD
private int nSplitter; //Count of Splited Downloading File L)kb (TH
(<]\,pP0_
#514a(6
public SiteInfoBean() pIZLGsu[
{//nSplitter的缺省值为5 r6F{
//default value of nSplitter is 5 >+Sv9S
this("","","",5); e'k;A{Oh
} ueWR/
iioct_7,g<
bxd3
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 9:9N)cNvfX
{ ?$30NK3G
sSiteURL= sURL; .q5J^/kr
sFilePath = sPath; 54ak<&?
sFileName = sName; r3+<r<gs
this.nSplitter = nSpiltter; aW`:)y&f
zmy4tsmX
0v_6cYA
} L~*|,h
xQNw&'|UU
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public String getSSiteURL() Xk{!' 0
{ Z-^uM`],G
return sSiteURL; ]+}ZfHp
} ]~j_N^oZ1X
pr62:
(*Gi~?-
public void setSSiteURL(String value) RL7C YB
{ =F'l's^j
sSiteURL = value; fnLR
} + >T7Q`64
vh9kwJyT
b{~fVil$y
public String getSFilePath() %+AS0 JhB
{ Wphe%Of
return sFilePath; ewb*?In
} ntrY =Y
8Zcol$XS'
=&di4'`
public void setSFilePath(String value) (l\a'3a.
{ }G>v]bV0V
sFilePath = value; Ez06:]Jd
} c[(yU#@
0OleO9Ua
A5CdLwk
public String getSFileName() i&A{L}eCr:
{ a~8:rW^
return sFileName; ]%gp?9wy
} 33=Mm/<m$P
x2 w8zT6M
R'*<A3^
public void setSFileName(String value) ^-gfib|VGe
{ _v1bTg"?
sFileName = value; -rEeKt
} ljNzYg~-
*0=fT}&!
Nc G,0K
public int getNSplitter() KotPV
{ T{_1c oL
return nSplitter; @PYW|*VS
} E)KB@f<g*
f:_=5e +
Oq #o1>
public void setNSplitter(int nCount) DY)D(f/&3
{ n?y'c^
nSplitter = nCount; ^c/mj9M#C
} B1|?RfCe
} y<O@rD8iA
8B}'\e4i
!a' K&
/* IkSX\*
**Utility.java e{v,x1Y_z(
*/ pG)9=X!9
package NetFox; P#AAOSlLV
"V:
v*&Uk'4E
public class Utility { Vh 2Bz
k%{ l4
/6Y0q9
public Utility() R ^HohB
{ }BA9Ka#%
/uK)rG F
Bs_S.JP<`
} KjO-0VMN3
gsnP!2cR
//线程睡眠 =hJfL}&O3
public static void sleep(int nSecond) +2- qlU
{ S$S_nNq
try{ y:qx5Mi
Thread.sleep(nSecond); }$^]dn@
} %p<$|'
catch(Exception e) CT|z[^
{ (F/HU"C
e.printStackTrace (); 6_W<hevI
} smQ4CLJ
} >NJjS8f5
2K3MAd{
//日志 EY So=
public static void log(String sMsg) BTOA &Ag
{ 0Xp nbB~~I
System.err.println(sMsg); %_>Tcm=
} 1#/6r :
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[6O04"6K
public static void log(int sMsg) @XeEpDn]
{ DNmb[
System.err.println(sMsg); $"/UK3|d
} DLU[<!C
} VK9Q?nu
5(423"(y
Ud$Q0m&
/* ])eOa%
**TestMethod.java U9x4j_.q
*/ pfR"s:#
package NetFox; +eU`H[iu
5f8"j$Az
+Dd"41
public class TestMethod { v5B" A"N
R|-6o)$
6*sw,sU[y
public TestMethod() q1H~ |1
{ ///xx/weblogic60b2_win.exe 9t#P~>:jY}
try{ t @;WgIp(&
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7LG+$LEz
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); mU>&ql?e
SiteFileFetch fileFetch = new SiteFileFetch(bean); Jms=YLIAA
fileFetch.start(); expxp#S
} q1STRYb
catch(Exception e){e.printStackTrace ();} <]~ZPk[
Og=[4?Kpk
4e}{$s$Xx
} *vb^N0P
n|6?J_{<b>
'm[6v}
public static void main(String[] args) 2%5?Fn=
{ %Mh Q
new TestMethod(); p<q].^M
} ,6DD=w0r
} }~rcrm.
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