http断点续传简单实现（java)

亚文隆

级别: 经院学前班

发帖: 8

铜板: 1641

人品值: 95

贡献值: 0

交易币: 0

好评度: 8

信誉值: 0

金币: 0

所在楼道

只看楼主更多操作楼层直达

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)); R,d70w (_
} L}e"nzTE6I
for(int i=0;i<nEndPos.length-1;i++) `}k&HRn
{ 1jUhG2y
nEndPos = nStartPos[i+1]; E<zT
} ~uhyROO,G"
nEndPos[nEndPos.length-1] = nFileLength; Ckl7rpY+
} 5UrXVdP
} Ie^Dn!0S
G*vpf~q?
LH3N}J({
//启动子线程 1WUFk?p
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; %vf2||a$BS
for(int i=0;i<nStartPos.length;i++) |"Xi%CQ2
{ wZ]BY;
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), m'Ekp
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), o-Q]Dk1W
nStartPos,nEndPos,i); -CU7u=*b
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); [}9XHhY1O=
fileSplitterFetch.start(); I |<+'G
} ctc`^#q
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), PxP?hk
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); :kp
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", :]u}xDv3
nEndPos = " + nFileLength); hdsgOu
// fileSplitterFetch[nPos.length-1].start(); AjL?Qh4
X>6~{3
MUCJ/GF*
//等待子线程结束 ZyS;+"
//int count = 0; aCUV[CPw
//是否结束while循环 0'V-
boolean breakWhile = false; SQ^^1.V&/Y
G>q{~HE1
O)U$Ef
while(!bStop) `jUS{ 3^
{ o%4&1^ Vg
write_nPos(); (}~eD
Utility.sleep(500); [KimY
breakWhile = true; Kc9mI>uH
t'=~"?T/o
e&H<lT
for(int i=0;i<nStartPos.length;i++) j quSR=
{ -9H!j4]T?
if(!fileSplitterFetch.bDownOver) _~wV{ yp
{ q*RaX 4V
breakWhile = false; =qS^Wz.
break; 3f:1D=f
} ];b!*Z
} B GEJiLH
if(breakWhile) LKf5r,C
break; wWOT*R_
Z z;<P
-EkDG]my
//count++; ,I2reG
//if(count>4) m|ERf2-
// siteStop(); T24#gF~
} S)'q:`tZo
QnP?;
vZ nO
System.err.println("文件下载结束！"); 8v)~J}[Bz
} Y3MR:{}
catch(Exception e){e.printStackTrace ();} S^Wqa:;
} C(t6;&H
R 6yvpH
3 ?|; on
//获得文件长度 S9"y@F <
public long getFileSize() :7DVc&0
{ Etr8lm E
int nFileLength = -1; E'BH7JV
try{ 4|Gs(^nU
URL url = new URL(siteInfoBean.getSSiteURL()); <C.$Db&9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); J|2Hqd
httpConnection.setRequestProperty("User-Agent","NetFox"); W'2-3J
l#vw L15
D917[<$
int responseCode=httpConnection.getResponseCode(); v$Y1+Ep9
if(responseCode>=400) lRATrp#T
{ 8apKp?~yW
processErrorCode(responseCode); Tk#&Ux{ZJ
return -2; //-2 represent access is error ^a#&wW
} K<7T}XzU$
!qGx(D{\
}zS&H-8K
String sHeader; Z=t#*"J
&CeF^
v"('_!
for(int i=1;;i++) zm3MOH^a
{ z.9FDQLp
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); cA*X$j6
//Utility.log(in.readLine()); soVZz3F
sHeader=httpConnection.getHeaderFieldKey(i); qT>& v_<
if(sHeader!=null) .'2gJ"?,
{ dt0E0i
if(sHeader.equals("Content-Length")) e}O-I
{ BM$tywC
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); M>H^<N}'A
break; xE-`Bb
} 'SD|ObBY
} er7/BE&
else Y./}zCT
break; ]-Y]Q%A4
} 4C9"Q,o%&
} ![hhPYmV
catch(IOException e){e.printStackTrace ();} }}bi#G:R+
catch(Exception e){e.printStackTrace ();} H6CGc0NS+
;s B:s9M
f`]E]5?
Utility.log(nFileLength); *2C79hi1
qjEWk."
!2M[
return nFileLength; ,lS-;.
} #.L0]Uqcp
[ma#8p)
oS|~\,p"
//保存下载信息（文件指针位置） Q2pboZ86
private void write_nPos() uZ?CVluP
{ #~-&&S4a.J
try{ ^8*SCM_A
output = new DataOutputStream(new FileOutputStream(tmpFile)); )Gp\_(9fc
output.writeInt(nStartPos.length); M"l rwun^
for(int i=0;i<nStartPos.length;i++) /(pD^D
{ >rS<!e%
// output.writeLong(nPos); Rpd/9x.)&
output.writeLong(fileSplitterFetch.nStartPos); ;)pV[3[
output.writeLong(fileSplitterFetch.nEndPos); {1U*:@j
} glX2L~
output.close(); =X5&au o
} ^PR,TR.
catch(IOException e){e.printStackTrace ();} f4y;K>u7p
catch(Exception e){e.printStackTrace ();} 3udIe$.Q
} >N1]h'q>
m7eIhmP
N4DDH^h
//读取保存的下载信息（文件指针位置） $$f$$
private void read_nPos() KXfW&d(Pk
{ A.x}%v,E
try{ Zt0%E<C{
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 207oEO]
int nCount = input.readInt(); iT9Ex9RL
nStartPos = new long[nCount]; EAXU{dRV
nEndPos = new long[nCount]; B(Q.a&w45t
for(int i=0;i<nStartPos.length;i++) &u\z T P
{ `e=n(D
nStartPos = input.readLong(); UKQ&TV}0
nEndPos = input.readLong(); TZyQOjUu
} n(xlad
input.close(); SWd[iD
} LVl0:!>~
catch(IOException e){e.printStackTrace ();} &B0&183
catch(Exception e){e.printStackTrace ();} Y]Vc}-a(h
} J15T!_AW<
>Io7h#[u
Y8{1?LO
private void processErrorCode(int nErrorCode) #LgoKiP!Y
{ gH)B` @
System.err.println("Error Code : " + nErrorCode); j6(IF5MqP
} B2WX#/lgd
% peb{i
<OfzE5
//停止文件下载 { (,vm}iFL
public void siteStop() A0u:Fm{E
{ IqKXFORiNI
bStop = true; gc[J.[
for(int i=0;i<nStartPos.length;i++) ;]x5;b9`
fileSplitterFetch.splitterStop(); pAmI ](
V46[whL%r
DC7}Xly(
} "FvlZRfXj
} >*xzSd?\
//负责部分文件的抓取 q\Kdu5x{
**FileSplitterFetch.java =PM#eu
*/ F|{?GV%hF
package NetFox; IOqyqt'
Jo+C!kc
l #z`4<
import java.io.*; }"H900WE|
import java.net.*; Lb 4!N`l
1M+!cX
Bd[Gsns
public class FileSplitterFetch extends Thread { jhM|gV&
8}T3Fig,q
R)Fl@ Tn
String sURL; //File URL L-gF$it\*b
long nStartPos; //File Snippet Start Position ^-Ji]5~
long nEndPos; //File Snippet End Position ^IkMRlJh%
int nThreadID; //Thread's ID qrYeh`Mv
boolean bDownOver = false; //Downing is over wuQkeWxJ
boolean bStop = false; //Stop identical \Da$bJ
FileAccessI fileAccessI = null; //File Access interface 2GS2,
tRCd(Z,WY
_lqAxWH
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException x%&V!L
{ K\Q 1/})
this.sURL = sURL; T/5UlW|\
this.nStartPos = nStart; a9-;8`fCR
this.nEndPos = nEnd; a9Rh
nThreadID = id; p?nVPTh
fileAccessI = new FileAccessI(sName,nStartPos);//定位 kk#d-! $[
} wX;NU4)n
TA7w:<
iJeT+}
public void run() oGJI3Oh
{ &>{L"{
while(nStartPos < nEndPos && !bStop) e~dU "
{ 2&#iHv
'9XwUQx
`#F>?g$2
try{ 4R6 .GO
URL url = new URL(sURL); |lY8u~%
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); ccAEN
httpConnection.setRequestProperty("User-Agent","NetFox"); k2;yl_7
String sProperty = "bytes="+nStartPos+"-"; u}_q'=<\
httpConnection.setRequestProperty("RANGE",sProperty); P6rL;_~e
Utility.log(sProperty); Jo]g{GX[
p9J(,}
\W!<xE
InputStream input = httpConnection.getInputStream(); d[de5Xra
//logResponseHead(httpConnection); ;d:7\
mi?Fy0\
&#.&xc2sRZ
byte[] b = new byte[1024]; uIBV1Qz
int nRead; o?=u#=
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) 5Jp>2d
{ #=rI[KI
nStartPos += fileAccessI.write(b,0,nRead); WObfHAp.
//if(nThreadID == 1) gnt[l0m
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); U*t`hn-xs
} GS@ wG
?(N(8)G1
^z1WPI
Utility.log("Thread " + nThreadID + " is over!"); 3? "GH1e
bDownOver = true; m`t7-kiZ
//nPos = fileAccessI.write (b,0,nRead); ;(A'XA4 6N
} .KV?;{~q@
catch(Exception e){e.printStackTrace ();} KT}}=st%
} 'tc$#f^:
} 1'=brc YR
~ lS3+H
<W1!n$V ]
//打印回应的头信息 71eD~fNdx
public void logResponseHead(HttpURLConnection con) EC7o 3LoND
{ g.'4uqU
for(int i=1;;i++) /D~:Ufw
{ VrDvd
String header=con.getHeaderFieldKey(i); U i;o/Z3
if(header!=null) Q"\[ICu!,
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 'RhMzPmY>
Utility.log(header+" : "+con.getHeaderField(header)); v^pE=f*/
else /3fo=7G6
break; $W)FpN;CW/
} [}Nfs3IlBw
} vwg\qKqSM
;2$^=:8
FD8aO?wvg
public void splitterStop() @|M10r9E
{ -?ip?[Z
bStop = true; t+pI<c^]y
} E:%%Dm
5s0H4?S
I6UZ_H'E
} St?vd+(>
Pai{?<zGi
,ihTEw,t(
/* ,}bC
**FileAccess.java 4Hu.o7
*//文件访问(定位，写) +Q{jV^IT9
package NetFox; yjr!8L:m
import java.io.*; F3?v&
";Lpf]<
Eh JYdO[e
public class FileAccessI implements Serializable{ Ly3^zFW
t4nAy)I)P
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 6$IAm#
RandomAccessFile oSavedFile; \wMr[_LW
long nPos; =oSv=xY
G.9?ApG9
d6_ CsqV
public FileAccessI() throws IOException #T+%$q [:
{ *@/!h2
this("",0); ?g!py[CrE
} m'Wz0b^BO
G|.>p<q
o-R;EbL
public FileAccessI(String sName,long nPos) throws IOException ,Xao{o(
{ T*z >A
oSavedFile = new RandomAccessFile(sName,"rw"); '9-8_;
this.nPos = nPos; NoV2<m$
oSavedFile.seek(nPos); IGVNX2
} 2rne=L
T-eeYw?Yf
]^"*Fdn
public synchronized int write(byte[] b,int nStart,int nLen) gVk_<;s
{ m"NZ;*d'
int n = -1; &c0U\G|j
try{ 8hGp?Ihu
oSavedFile.write(b,nStart,nLen); /9;)zI
n = nLen; ?%F*{3IP
} ?~;G)5
catch(IOException e) rj<r6
{ GKSfr8US4
e.printStackTrace (); N^B YNqr
} 4$@)yZ
AW1691Q
Zn|vT&:Hg
return n; hQvSh\p
} 7$k[cL1
?u"MsnCXYn
sd xl@
} V07e29w
fHdPav f,S
L@XhgQ
/* r1]shb%J?
**SiteInfoBean.java 6MqJy6
*/ Rcfh*"k
package NetFox; E$T)N U\
?dY}xE
}hv>LL
public class SiteInfoBean { PSNfh7g
aHvTbpJ
g`k_o<'JC
private String sSiteURL; //Site's URL IMpEp}7
private String sFilePath; //Saved File's Path +h.$<=
private String sFileName; //Saved File's Name G$<FQDvs
private int nSplitter; //Count of Splited Downloading File LcI,Dy|P
=rFgOdj
17 Hdj
public SiteInfoBean() i!@L`h!rw
{//nSplitter的缺省值为5 icOh/G=N;
//default value of nSplitter is 5 ;Z\jX[H
this("","","",5); WgF Xv@Jjt
} >LRt,.hy6
$fR[zBxA
2&S*> (
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) CXwDG_e
{ QK)"-y}"g
sSiteURL= sURL; Pfj{TT.#L
sFilePath = sPath; v,#*%Gn`%
sFileName = sName; -}_-#L!Q
this.nSplitter = nSpiltter; A M8bem~
hosw :%
GSj04-T"
} ]{;=<t6
C(qqGK{
qc;9{$?xV
public String getSSiteURL() 481J=8H
{ n@r'b{2;l
return sSiteURL; #Y6'Q8gf
} B/hL
:yO.Te F
zcnp?%
public void setSSiteURL(String value) {L^b['h@
{ \x\_I1|
sSiteURL = value; H}5zKv.T
} _7Z|=)
xrd@GTaI
]"Z*Hq z
public String getSFilePath() G41 gil6k
{ ;dgxeP;mp
return sFilePath; \}[{q
} 7)aitDD
Yz4)Q1
+c$]Q-(
public void setSFilePath(String value) L>VZ-j
{ huVw+vAA
sFilePath = value; Y?G\@6
} GZXBzZ}
&0! f_
t-7^deG'/n
public String getSFileName() KKpO<TO
{ /3`#ldb%}
return sFileName; Nb;xJSlox
} U"\$k&
A<-Prvryt
`D)ay
public void setSFileName(String value) V8AF;1c?-'
{ "#Ov!t
sFileName = value; qOOF]L9r%u
} 1haNca_6,
1UG5Q-
n-iy;L^b
public int getNSplitter() Ws2SD6!4`
{ ti6\~SY
return nSplitter; sDNV_} h
} @n<y[WA
)c~1s
TTB1}j+V6
public void setNSplitter(int nCount) %@JNX}Y'
{ zzmZ`Ya
nSplitter = nCount; 5cLq6[uO
} 2p'ujAK
} ACQbw)tiv}
' *hy!f]
Mle@.IIT
/* qbu>YTj
**Utility.java %tx~CD
*/ $@]tTz;b
package NetFox; N$u;Q(^
d:KUJ Y.
2BTFK"=U
public class Utility { F<SCW+>z2a
g-B~"tp
+%yVW f
public Utility() m|mY_t
{ cH$zDm1
HzADz%~
)C>4?)
} 'EF\=o)^Y
l+# l\q%l
//线程睡眠 rKZ1 c,y
public static void sleep(int nSecond) |a!AgvNF
{ FFE IsB"9
try{ +<cvyg5U
Thread.sleep(nSecond); h4@v.GI
} N^,@s"g
catch(Exception e) 9Z! j
{ jpND"`Q
e.printStackTrace (); <PBrW#:'
} bcgh}D
} HK~uu5j
?$rSbw
//日志 >:5^4/fo*
public static void log(String sMsg) I'"b3]DXG
{ +(>!nsf
System.err.println(sMsg); f-at@C1L%L
} *eE&ptx1
S;0,UgB1
*Q=3v
public static void log(int sMsg) !'-K>.B
{ UzLe#3MU
System.err.println(sMsg); 8;'fWV? U
} YyI4T/0s_
} -b1VY4m-
}%j@%Ep[
u_0&`zq
/* %lL^[`AR
**TestMethod.java 7|~j=,HU+Z
*/ FcR(uv<
package NetFox; >s\j/yM
FScE3~R
l=jfgsjc
public class TestMethod { d,"?tip/SX
_)4YxmK%
etY/K0
public TestMethod() /.leY$
{ ///xx/weblogic60b2_win.exe 4AI\'M"d
try{ C^uH]WO
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); 7C7eXJ9q
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); Z,'#=K
SiteFileFetch fileFetch = new SiteFileFetch(bean); ],rtSUO
fileFetch.start(); W/dl`UDY
} *G{%]\s?
catch(Exception e){e.printStackTrace ();} e}qG_*
5w:
@=KuoIV
} !P*1^8b`f
8= jl]q$<
+J`EBoIo
public static void main(String[] args) uo`O$k<;
{ @^Tof5?F?
new TestMethod(); "tuBfA+f
} w#v8a$tT
} hr%O4&sa
点击下载更多相关资料