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)); S^D ~A8u
} _W#27I
for(int i=0;i<nEndPos.length-1;i++) >Q5E0 !]
{ ^ad> (W
nEndPos = nStartPos[i+1]; !b _<_Y{l
} s[s6E`Q
nEndPos[nEndPos.length-1] = nFileLength; ]\r~"*TZ
} 9y]$c1
} 1<59)RiO>
rhn*kf{8
^QW%<X
//启动子线程 R!pV`N
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; "?qu(}|
for(int i=0;i<nStartPos.length;i++) 5-mJj&0:!
{ 'T|.<u@~
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), XcfTE m
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), l]v *h0!
nStartPos,nEndPos,i); sCRBKCR?
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); <U,T*Ql1x
fileSplitterFetch.start(); dnIBAe
} U-n33ty`H
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 'pm2C6AC
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); (vj2XiO^+
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", zLh ~x
nEndPos = " + nFileLength); rX{|]M":T
// fileSplitterFetch[nPos.length-1].start(); =h_4TpDQ
\v-> '
@#Xzk?+
//等待子线程结束 Ha+FH8rZ
//int count = 0; D *LZ_
//是否结束while循环 E!Fy2h>[Z
boolean breakWhile = false; 0|^x[dh
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BxZop.zwE(
while(!bStop) -ZyFUGd%
{ ([9h.M6v
write_nPos(); .PAkW2\#
Utility.sleep(500); uqO51V~
breakWhile = true; J0=`n(48B
HWefuj
M$~h(3
for(int i=0;i<nStartPos.length;i++) f1~3y}7^Jq
{ [#9ij3vxd
if(!fileSplitterFetch.bDownOver) C,IN+@
{ Gg.w-&
breakWhile = false; 9C4l@jrF
break; r 2
} lP9I\Ge&
} VhW;=y>}
if(breakWhile) /d{L]*v)]
break; +qz)KtJS
9lD,aOb
~hxB Pn."
//count++; q]r!5&Z
//if(count>4) QKP9*dz
// siteStop(); k=~?!+p7
} \W(p)M
pKH4?F
N0qC/da1
System.err.println("文件下载结束！"); H|TzD"2N
} Bw#ubQJ8}
catch(Exception e){e.printStackTrace ();} #63/;o:l$
} {X =\
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.e"jnP~
//获得文件长度 U|Jo[4A
public long getFileSize() 6/-!oo
{ zEhy0LLm
int nFileLength = -1; #VO2O0GR
try{ :,ym)|YV
URL url = new URL(siteInfoBean.getSSiteURL()); Wig0OZj
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); C3b'Q
httpConnection.setRequestProperty("User-Agent","NetFox"); 9=kTTFs
bL&]3n9Rwu
)Xh_q3=
int responseCode=httpConnection.getResponseCode(); 5PPy+36<~
if(responseCode>=400) eY(usK
{ U1"t|KW8
processErrorCode(responseCode); @B'Mu:|f
return -2; //-2 represent access is error V!opnLatYS
} -DuiK:mp
*g,?13Q_
ZK ?x_`w
String sHeader; R_N<j
?}]kIK}MC
7O9s5
for(int i=1;;i++) f C^l9CRY
{ pS<b|wu?f
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); $3[cBX.=
//Utility.log(in.readLine()); #y*=UV|h
sHeader=httpConnection.getHeaderFieldKey(i); K?;p:
if(sHeader!=null) '0O[dN
{ eB\r/B]
if(sHeader.equals("Content-Length")) "aBd0i&
{ z67=v9+7
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); fhY[I0;}$
break; x@Y2jM
} ,|4Ye
} wU ; f
else 1IlR
break; O\LW 8\M
} |ber:1
} R`**!ku
catch(IOException e){e.printStackTrace ();} #PrV)en
catch(Exception e){e.printStackTrace ();} :1lE98=
XF7W'^
-oZac
Utility.log(nFileLength); wqwJpWIe
t@u\ 4bv
cV{ZDq
return nFileLength; y{{EC#
} 9V66~Bf5
Me}TW!GC
>#:/ GN?
//保存下载信息（文件指针位置） PD}R7[".>
private void write_nPos() _RW[]MN3*
{ %)/f; T6
try{ ).]m@g:ew
output = new DataOutputStream(new FileOutputStream(tmpFile)); Hr+-ndH!Pq
output.writeInt(nStartPos.length); VBX# !K1Q
for(int i=0;i<nStartPos.length;i++) `es($7}P_W
{ [[e|GQ
// output.writeLong(nPos); p-pw*wH0
output.writeLong(fileSplitterFetch.nStartPos); -/-6Td1JY>
output.writeLong(fileSplitterFetch.nEndPos); #8z,'~\
} w}Upa(dU
output.close(); 2&Byq
} R2$U K
catch(IOException e){e.printStackTrace ();} ,OKM\N,
catch(Exception e){e.printStackTrace ();} yo*iv+l
} /,Rca1W
}K>HS\e
j>o +}p?3I
//读取保存的下载信息（文件指针位置） bJ|?5
private void read_nPos() =GQ^uVf1
{ @1F'V'
try{ 0H3T'J%r
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); Q@2tT&eL
int nCount = input.readInt(); _=L;`~=C9e
nStartPos = new long[nCount]; u!uDu,y
nEndPos = new long[nCount]; .UrYF 0
for(int i=0;i<nStartPos.length;i++) W"kw>JEt
{ VM]IL%AN
nStartPos = input.readLong(); vs1Sh?O
nEndPos = input.readLong(); cY2-T#rL
} N}Ks[2
input.close(); ,z1!~gIal
} ,w%oSlOu
catch(IOException e){e.printStackTrace ();} i$ L]X[
catch(Exception e){e.printStackTrace ();} eUkoVr
} JQ_gM._3
KupMndK
CjQ"oQw
private void processErrorCode(int nErrorCode) Ys$YI{
{ v1C.\fL
System.err.println("Error Code : " + nErrorCode); Tq84Fn!HJ>
} @LKG\zYBu
_g 4/%
<8)s
//停止文件下载 F36ViN\b
public void siteStop() yb{Q,Dz
{ =$8@JF'
bStop = true; [S]!+YBK
for(int i=0;i<nStartPos.length;i++) d=Do@) m|
fileSplitterFetch.splitterStop(); {TncqA
HJ qQlEq
F4rKFMr
} sdf%
} *kQCW#y0
//负责部分文件的抓取 }E5#X R
**FileSplitterFetch.java Iv(Qa6(
*/ naIv=
package NetFox; Iz)hz9k
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QP%kL*=8
import java.io.*; 6!B^xm.R@
import java.net.*; (kC} ,}
@%<?GNSO
yvz?4m"_yB
public class FileSplitterFetch extends Thread { nnE_OK!}T
FxfL+}?Q
(.1 rtj
String sURL; //File URL Q)S>VDLA
long nStartPos; //File Snippet Start Position ,k~j6Z
long nEndPos; //File Snippet End Position umjhG6
int nThreadID; //Thread's ID y|.fR>5
boolean bDownOver = false; //Downing is over v'@b.R,
boolean bStop = false; //Stop identical *sw-eyn(
FileAccessI fileAccessI = null; //File Access interface ( f,J_
_Dj<Eu_
23-t$y]
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException h/Hl?O8[
{ u<]mv
this.sURL = sURL; XocsSs
this.nStartPos = nStart; f>r3$WKj
this.nEndPos = nEnd; ^IGyuj0]jG
nThreadID = id; %X9b=%'+
fileAccessI = new FileAccessI(sName,nStartPos);//定位 \V^*44+ <!
} Ud#X@xK<h
Ka]@[R6e
>`89N'lZBm
public void run() MCeu0e^)
{ 0)AM-/"
while(nStartPos < nEndPos && !bStop) BF36V\
{ =4zNo3IvL+
vJRnBq+y
] *-;' *
try{ mP pvZ
URL url = new URL(sURL); Kej|1g1f
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y}LLOj@L
httpConnection.setRequestProperty("User-Agent","NetFox"); ~XUOWY75
String sProperty = "bytes="+nStartPos+"-"; uxOJ3
httpConnection.setRequestProperty("RANGE",sProperty); 4;C*Fa
Utility.log(sProperty); $_C+4[R?
_1sMYhI
L)F1NuR
InputStream input = httpConnection.getInputStream(); ]4Y/xi-
//logResponseHead(httpConnection); !:"-:O}>=,
lc[XFc
a}KK{Vqo`
byte[] b = new byte[1024]; k&)K(
int nRead; CV&zi6
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) @P:R~m2
{ 4.|-m.a
nStartPos += fileAccessI.write(b,0,nRead); S Pn8\2Cj
//if(nThreadID == 1) 5VR.o!h3I
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); FaFp_P?
} /vjGjb=3U
s=d+GMa
\sK:W|yy
Utility.log("Thread " + nThreadID + " is over!"); 5vTv$2@
bDownOver = true; U:]MgZWn
//nPos = fileAccessI.write (b,0,nRead); AkrTfi4hC
} c>ad0xce6
catch(Exception e){e.printStackTrace ();} p jKt:R}
} QjA&IZEC
} b~_B [cf
4:vTxNs&S
z)lM2x>|*
//打印回应的头信息 pkXv.D`
public void logResponseHead(HttpURLConnection con) HU &)
{ r6`\d k
for(int i=1;;i++) m0A#6=<
{ i&`!|X-=R
String header=con.getHeaderFieldKey(i); fVe@YqNa
if(header!=null) I%@e@Dm,h
//responseHeaders.put(header,httpConnection.getHeaderField(header)); nr OqH
Utility.log(header+" : "+con.getHeaderField(header)); &<au/^F
else _(C^[:s
break; QDS0ejhp
} gnt45]@{
} (I4y[jnD
v f`9*xF
P##Z[$IJ3
public void splitterStop() #?9Q{0e
{ <uZPqi||
bStop = true; bV@7mmz:X+
} a3q\<"|
(ZV;$N-t
HZ }6Q
} %>Bko,ET
@(-yrU
+?;j&p
/* ~m=$VDWm
**FileAccess.java Z>8eD|m%2
*//文件访问(定位，写) "B#Y-
package NetFox; A 4j<\xL
import java.io.*; 3gpo %
c45tmul
.Gh%p`<
public class FileAccessI implements Serializable{ lop uf/U0
B{p4G`$i1
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 yRC3 .[
RandomAccessFile oSavedFile; }W$8M>l
long nPos; 7JI:=yY!>:
!z MDP/V
b^ sb]bZW
public FileAccessI() throws IOException zmI5"K"'F
{ XA1f' Kk
this("",0); vM`7s[oAK
} JSgpb?(
=}v ;1m
h*s`^W3
public FileAccessI(String sName,long nPos) throws IOException :uo[&&c
{ EKuSnlTXba
oSavedFile = new RandomAccessFile(sName,"rw"); IIxJqGN:
this.nPos = nPos; e_/x&a(i8
oSavedFile.seek(nPos); ~:[!Uyp0b
} G>%AZr{M
3B{[%#vO
?,07;>&
public synchronized int write(byte[] b,int nStart,int nLen) ]#zZWg zv
{ ;i\C]*
int n = -1; F$Q04Qw
try{ RN[]Jt#6
oSavedFile.write(b,nStart,nLen); <Ct_d Cc
n = nLen; (#o t^
} !v9lk9SV
catch(IOException e) )TU<:V
{ h*Je35
e.printStackTrace (); tPU-1by$
} bLbR IY"l
6tn+m54_
sTkkM9
return n; /L&M,OUcr.
} X|b2c+I
Oz{%k#X-
Qz+sT6js-
} jl}$HEI5m}
d(7NO;S8
:l,OalO
/* h^oH^moq<
**SiteInfoBean.java #.ct5
*/ }ptMjT{9
package NetFox; LjaGyj>)
UTCzHh1
,l HLH
public class SiteInfoBean { {)@D`{$
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exDkq0u]
private String sSiteURL; //Site's URL qu~X.pW
private String sFilePath; //Saved File's Path zizk7<?L.
private String sFileName; //Saved File's Name lY'N4x7n
private int nSplitter; //Count of Splited Downloading File rk|@B{CA;
Zx{96G+1
bik*ZC?E
public SiteInfoBean() K2rzhHfb
{//nSplitter的缺省值为5 T8XY fcc*h
//default value of nSplitter is 5 U O<:.6"
this("","","",5); g97]Y1g
} xAhxD|4_
pQWHG#?7
#NNewzC<*
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) NfzF.{nh
{ ^jD1vUL 2:
sSiteURL= sURL; v`DI<Lt
sFilePath = sPath; sx 9uV
sFileName = sName; A:# k
this.nSplitter = nSpiltter; =Z,5$6%)
M#,Q ^rH#
j6g@tx^)'
} Rc[0aj:
zY=jXa)K~
OH6^GPF6
public String getSSiteURL() &@v<nO-
{ t'1Y@e
return sSiteURL; YF[f Z
} 9V 0}d2d
N|:'XwL
H?`g!cX
public void setSSiteURL(String value) qpp/8M
{ M\D]ml~
sSiteURL = value; ;inzyFbL=
} p_2pU)%
DWiBG
L":bI&V?:
public String getSFilePath() _P7tnXww
{ 1S:|3W
return sFilePath; CN&
} *>q/WLR
sZhMa>
'Ot,H_pE
public void setSFilePath(String value) a|_p,_
{ 9YN?
sFilePath = value; @jy41eIo
} K#mOSY;}
\7v)iG|#G&
-YGbfd<wq
public String getSFileName() /rc%O*R
{ 1(#;&:$`i
return sFileName; d8o53a]
} NHQF^2\\
M+P$/Wk
^%>kO,
public void setSFileName(String value) mD58T2Z
{ jd-glE,Y/
sFileName = value; w:i:~f .
} ZC0-wr\
`#mK*Buem}
oG oK,
public int getNSplitter() Shr,#wwM`B
{ FnFb[I@eu
return nSplitter; G"SBYU
} {zLhiUH a0
3ec`Wa
iw9Q18:I}
public void setNSplitter(int nCount) 5F"|E-;
{ =aG xg57
nSplitter = nCount; -yAQ
} vH[47CvG5
} s)J(/
#qBr/+b
nY%5cJ`"
/* p#P~Q/;
**Utility.java |N/G'>TS
*/ q2aYEuu,
package NetFox; N)2f7j4C&
Z.PBu|Kx
V$`Gwr]|n
public class Utility { IM@tN L
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fwR_OB:$
public Utility() 7- d.ZG
{ <O<LYN+(
(!L5-8O
`)iY}Iu
} &[Xu!LP
4,Ic}CvM
//线程睡眠 \nNXxTxX!
public static void sleep(int nSecond) dihjpI_
{ }yn0IWVa
try{ g=L]S-e
Thread.sleep(nSecond); 56lCwXCgA
} dUrElXbXd
catch(Exception e) ||7x;2e
{ LW6ZAETyL
e.printStackTrace (); VosZJv=
} f|7\DeY9U
} #N(= 3Cj
9m2, qr|
//日志 +n0r0:z0
public static void log(String sMsg) p{A}pnjf
{ '@|_OmcY
System.err.println(sMsg); 1$/MrPT(b
} $@-P5WcRs
zET^T5>:
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public static void log(int sMsg) Q#I"_G&{
{ C*=Xk/0
System.err.println(sMsg); K7knK
} fEf_F r
} $``1PJoi
!LMN[3M_
+j_;(Gw7
/* |y;}zQB-dH
**TestMethod.java )> ,wj
*/ d_UN0YT<
package NetFox; B(a-k?
ia&AW
(_kp{0r#
public class TestMethod { g,tjm(
b \KL;H/
M-L2w"
public TestMethod() LsEXM-
{ ///xx/weblogic60b2_win.exe H={DB
try{ \J..*,'
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 9_s6l
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); ='ZRfb&
SiteFileFetch fileFetch = new SiteFileFetch(bean); )~4II.`%^
fileFetch.start(); Mv544>:
} EC2+`HJ"
catch(Exception e){e.printStackTrace ();} EKEjv|_)
$EZN1\
ZX!r1*c 6
} $n^MD_1!
@bM2{Rh:
&X@Bs-
public static void main(String[] args) sIG7S"k>p
{ <U5wB]]
new TestMethod(); qf@q]wtar
} F^"_TV0va
} `e9$,h|4
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