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)); `, OG7hg
} @5N]ZQ9
for(int i=0;i<nEndPos.length-1;i++) smlpD3?va
{ ;rF\kX&Jh
nEndPos = nStartPos[i+1]; 2;k*@k-t
} h;p>o75O
nEndPos[nEndPos.length-1] = nFileLength; <c2E'U)X
} MI/MhkS ?
} 94h]~GqNi
&v56#lG
[4YTDEv%
//启动子线程 >"^ O"E
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; Nv#t:J9f
for(int i=0;i<nStartPos.length;i++) ;Y00TGU
{ 2^r<{0@n
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), 6</xL9#/
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), zBCtd1Xrni
nStartPos,nEndPos,i); A 9( x
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); 3x`|
fileSplitterFetch.start(); "un]Gc
} umjt]Gu[
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), }q_<_lQ
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); 2M.fLQ?
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", Kz~ps 5
nEndPos = " + nFileLength); j]{_s"O
// fileSplitterFetch[nPos.length-1].start(); :*I#n
_GV:HOBi
6V$Avg\6\
//等待子线程结束 N(;1o.~
//int count = 0; ,vr? 2k
//是否结束while循环 HJ9Kz^TnC
boolean breakWhile = false; t_o['F
_dqzB$JV
~5NXd)2+Ks
while(!bStop) Zq^At+8+
{ +[M6X} TQ
write_nPos(); [A~y%bI"
Utility.sleep(500); i`(XLi}k
breakWhile = true; -)w@f~Q
Dt}JG6S
|z9*GY6RU
for(int i=0;i<nStartPos.length;i++) ZGBd%RWjG_
{ /kE6@
if(!fileSplitterFetch.bDownOver) M||+qd W!
{ *{YlN}vA
breakWhile = false; T/b6f;t-s
break; 6"wlg!k8
} y`VyQWW
} IoxgjUa
if(breakWhile) d?ex,f.
break; gR&Q3jlIV
SzAJ2:qhl
B~6&{7xc%
//count++; PY_u/<u
//if(count>4) 34`'M+3
// siteStop(); 8*W#DH!
} .I7pA5V{#
^hG-~z<
UvJ}b
System.err.println("文件下载结束！"); @'w"R/,n-@
} :G [|CPm-
catch(Exception e){e.printStackTrace ();} c?tBi9'Y]
} q_Q/3rh
y0Fb_"}
69PE9zz
//获得文件长度 |N4.u _hM
public long getFileSize() sGi"rg#
{ S ^"y4-2
int nFileLength = -1; )SaGH3~*C
try{ YpWPz %`:
URL url = new URL(siteInfoBean.getSSiteURL()); {ME2ImD
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oL!EYbFD'Z
httpConnection.setRequestProperty("User-Agent","NetFox"); rxe>}ZO
,-$LmECg
9eGyyZg
int responseCode=httpConnection.getResponseCode(); 4qO+_!x{)
if(responseCode>=400) 6w*dKInG[-
{ ot,jp|N>f~
processErrorCode(responseCode); QCD.YFM
return -2; //-2 represent access is error :nh_k4S@v
} ?}Z1bH
K`yRr`pW
+Jlay1U&
String sHeader; 6o!!=}'E[
p09HL%~R
3r<~Q7e
for(int i=1;;i++) X@'uy<tI-
{ (lXGmx8
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); S{Kiy#ltWc
//Utility.log(in.readLine()); j:^#rFD4?
sHeader=httpConnection.getHeaderFieldKey(i); 9`T)@Uj2n
if(sHeader!=null) dV*]f$wQ
{ +dWDxguE{w
if(sHeader.equals("Content-Length")) |!1Y*|Q%s
{ (jnzT=y
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); &x=.$76
break; F<ZYh
} =qoWCmg"&
} zbXI%
else uX"H4lO~
break; }'5MK
} dWM'fg
} bo,_&4?
catch(IOException e){e.printStackTrace ();} szb_*)k
catch(Exception e){e.printStackTrace ();} G|[=/>~B
.\\DKh%
_mzW'~9wN
Utility.log(nFileLength); aKV$pC<[o
;PF`Wj
,QOG!T4
return nFileLength; +cD<:"L'g
} Qn^'
:<ka3<0%
<vnHz?71c
//保存下载信息（文件指针位置） b1?#81
private void write_nPos() Kc!}`Pm
{ }wWKFX
try{ ?# Mr
output = new DataOutputStream(new FileOutputStream(tmpFile)); 8/DS:uM
output.writeInt(nStartPos.length); QsGiclU
for(int i=0;i<nStartPos.length;i++) :lX!\(E2
{ H;D>|q
// output.writeLong(nPos); heltgRt
output.writeLong(fileSplitterFetch.nStartPos); )bA;?i
output.writeLong(fileSplitterFetch.nEndPos); gMv.V{vD
} )}''L{k-
output.close(); q?,).x nN
} kJWn<5%ayg
catch(IOException e){e.printStackTrace ();} K}2Erm%A@y
catch(Exception e){e.printStackTrace ();} ^aIPN5CK
} qBU-~"2t
hMzs*gK
/Y*WBTV'
//读取保存的下载信息（文件指针位置） 7@#>bE6
private void read_nPos() 4]rnY~
{ pny11C
try{ _geWE0 E
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); #mlS}~n
int nCount = input.readInt(); x"eRJii?
nStartPos = new long[nCount]; Xk:OL,c
nEndPos = new long[nCount]; _G_Cj{w
for(int i=0;i<nStartPos.length;i++) BoA/6FRi[
{ R7]l{2V#^
nStartPos = input.readLong(); k=2Lo
nEndPos = input.readLong(); =31"fS@
} *zNYZ#
input.close(); V @rI`~$
} {qDSPo
catch(IOException e){e.printStackTrace ();} 9 ^o-EC!_
catch(Exception e){e.printStackTrace ();} VJ84?b{c W
} y9_V
~aw.(A?MI
]~844Jp
private void processErrorCode(int nErrorCode) ioaU*%
{ h}-3\8 >
System.err.println("Error Code : " + nErrorCode); 1ofKt=|=
} XoXM^*Vk
,t}vz 7
-_ I_W&
//停止文件下载 -)s qc P
public void siteStop() KTK <gV9:
{ (w&F/ynO:
bStop = true; Us%T;gW
for(int i=0;i<nStartPos.length;i++) o-;E>N7t
fileSplitterFetch.splitterStop(); K7$x<5+)
yZd +^QN
zFfoqb#*g
} R= a|Blp
} liEPCWl&
//负责部分文件的抓取 O[# 27_dH
**FileSplitterFetch.java d[r#-h>dS
*/ 3E7ULK
package NetFox; D@C-5rmq
X"MB|Ny
fz;iOjr>
import java.io.*; >82@Q^O
import java.net.*; YgKZ#?*
w'L\?pI
mrTlXXz
public class FileSplitterFetch extends Thread { |].pDwgt
\Fl+\?~D
xrlmKSPa
String sURL; //File URL :d3bt~b'
long nStartPos; //File Snippet Start Position tzZ63@cm
long nEndPos; //File Snippet End Position + r!1<AAE$
int nThreadID; //Thread's ID ckV`OaRw4
boolean bDownOver = false; //Downing is over oV)~@0B&0
boolean bStop = false; //Stop identical avjpA?Vz
FileAccessI fileAccessI = null; //File Access interface aGK?x1_
@*>@AFnf\Z
4f@o mAM
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException ^<;V]cY`
{ =b38(\
this.sURL = sURL; U0=]
this.nStartPos = nStart; "ZHW2l Mf
this.nEndPos = nEnd; _\=`6`b)
nThreadID = id; `(T,+T4C5k
fileAccessI = new FileAccessI(sName,nStartPos);//定位 v. %R}Pa
} Xf0M:\w=M
Y;nZ=9Sw
Z1zVwHa_
public void run() :iFIQpk
{ ! N|0x`
while(nStartPos < nEndPos && !bStop) .e3NnOzyxS
{ %R1tJ(/
LY6;.d$J
H&F9J^rC
try{ A01AlK_B
URL url = new URL(sURL); Ny_lrfh)[
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Z:ni$7<.
httpConnection.setRequestProperty("User-Agent","NetFox"); 1[kMOp
String sProperty = "bytes="+nStartPos+"-"; -r#X~2tPzD
httpConnection.setRequestProperty("RANGE",sProperty); whonDG4WP
Utility.log(sProperty); @vpf[j
M@h|bN
CQwL|$)]Y
InputStream input = httpConnection.getInputStream(); G,TM-l_uw
//logResponseHead(httpConnection); Fd?"-
17D"cP
A3vUPWdDk
byte[] b = new byte[1024]; tcI}Ca>u
int nRead; x2@U.r"zo
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) ?!wgH9?8
{ 'jmTXWq*
nStartPos += fileAccessI.write(b,0,nRead); m1n.g4Z&*
//if(nThreadID == 1) W-Fu-Cz=
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); ZPc@Zr`z
} }>)@WL:q
lJ+0P2@h*
x8!ol2\`<
Utility.log("Thread " + nThreadID + " is over!"); XEC(P
bDownOver = true; Av?2<
//nPos = fileAccessI.write (b,0,nRead); \2nUa ;
} QF-LU
catch(Exception e){e.printStackTrace ();} UUF;p2{f
} 3VI4X
} Q s.pGi0W
pX/n)q[
zR `EU,
//打印回应的头信息 ~)qtply
public void logResponseHead(HttpURLConnection con) qud\K+
{ GFfq+=se
for(int i=1;;i++) 1J6,]M
{ "oWwc zzO
String header=con.getHeaderFieldKey(i); MepuIh
if(header!=null) 1mfs4
//responseHeaders.put(header,httpConnection.getHeaderField(header)); {*[\'!d--.
Utility.log(header+" : "+con.getHeaderField(header)); 994`ua+
else %Rz&lh/
break; 9m|kgY# 4
} p`nPhk,:b
} ;2@BO-3K
Vm5c+;
Qd=^S^}(
public void splitterStop() V?Z.\~
{ $KUos+%
bStop = true; qP2ekI:y
} 7a#4tqM#
)foq),2
hdnTXs@z
} ET_W-
4Y,R-+f
_2k]3z?
/* 1^_U;O:I
**FileAccess.java I/M_p^
*//文件访问(定位，写) 4 SHU
package NetFox; Rop'e8Q
import java.io.*; MS>t_C(
rSxxH]-
TlI<1/fP}
public class FileAccessI implements Serializable{ fBgEnz/
!_+8A/
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 IP``O!WP
RandomAccessFile oSavedFile; rEHkw '
long nPos; ^zEwA
[01.\eh
'\Jj8oJQj
public FileAccessI() throws IOException B.g[c97
{ y_*PQZ$c<
this("",0); {88gW\GL
} ZiYm:$CJ
"Vw m
t<T[h2Wd
public FileAccessI(String sName,long nPos) throws IOException ( {1e%
{ AjJURn0`,!
oSavedFile = new RandomAccessFile(sName,"rw"); _<=S_<$2
this.nPos = nPos; {o!KhF:[
oSavedFile.seek(nPos); NZP.0coY
} w?zKjqza=v
56e r`=ms
~/8M 3k/
public synchronized int write(byte[] b,int nStart,int nLen) 4(Ov1a>
{ .!1S[
int n = -1; 5k6mmiaKk
try{ <'fdkW
oSavedFile.write(b,nStart,nLen); &;XAuDw4+i
n = nLen; Eo\UAc
} '" X_B0k
catch(IOException e) KhCzD[tf
{ TMs,j!w?I
e.printStackTrace (); Mva3+T
} Z4A!U~
W%.v.0
L KCb_9
return n; U\veOQ;mW
} PqyA1
J4"mK1N(
-+7uy.@cS
} ?lbH02P{v
vKq^D(&cl
|o2sbLp
/* 7_.11$E=H
**SiteInfoBean.java ,g7.rEA
*/ a-"k/P#
package NetFox; i^_#%L
q}/WQ]p} <
uKz,SqX
public class SiteInfoBean { i `s|,"0o
e$u4vC~
c&X{dJWD
private String sSiteURL; //Site's URL o\88t){/kB
private String sFilePath; //Saved File's Path *[r!
private String sFileName; //Saved File's Name tG8jFou
private int nSplitter; //Count of Splited Downloading File %/c+`Wd/l$
b+6"#/s
oEx\j+}@n
public SiteInfoBean() ?Zc"C
{//nSplitter的缺省值为5 Rx*BwZ
//default value of nSplitter is 5 `%E8-]{uS
this("","","",5); X=6y_^
} P+!"wX0*N
i]=&
EyI}{6~F
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) 4-kZJ\]
{ !IC-)C,q
sSiteURL= sURL; v?0r`<Mn
sFilePath = sPath; &-czStQ
sFileName = sName; [U@*1
this.nSplitter = nSpiltter; "+z?x~rk
K]qM~v<A
yf?h#G%24
} -*~CV:2iq-
N7b1.]<
OdQT2PA_
public String getSSiteURL() /wxE1][.
{ hY*0aZ|(
return sSiteURL; &n[~!%(
} i\4hR?
osOVg0Gyj
+B'8|5tPX
public void setSSiteURL(String value) 4<lQwV6=
{ BaO1/zk
sSiteURL = value; Tzt,/e
} [L6w1b,
^9_UUzf\
c(U
public String getSFilePath() [w0/\]o
{ Z2Zq'3*
return sFilePath; 2[B4f7
} SR^_cpZoi
kF{*(r=.o
&(zfa&j|
public void setSFilePath(String value) X53mzs
{ 4"@GNk~e
sFilePath = value; 6AvHavA^Y
} R#n%cXc|
K7e4_ZGI
Y7GF$}%UL
public String getSFileName() tp:\j@dB
{ Um)>2|rp}
return sFileName; ? b[n|^wS
} C{Asp
MlJVeod
(>=7ng^
public void setSFileName(String value) YB)3X[R+0
{ E15vq6DKF
sFileName = value; ~gI{\iNF/
} "o&HE@t
n;8'`s
[U8$HQ+x
public int getNSplitter() 1z*kc)=JF8
{ b?Pj< tA
return nSplitter; -h-oMqgu(
} ,&7Wa-vf
:Pq.,s
659v\51*
public void setNSplitter(int nCount) 1/ZR*fa
{ 451'>qS
nSplitter = nCount; mPPk)qy
} ~=&t0D
} 85IMdZ7I
]~>K\i
y/? &pKH^
/* SQWafD
**Utility.java J4tcQ
*/ >p])it[q&$
package NetFox; 3Z>YV]YbeU
JI|6B
}wwe}E-e
public class Utility { \aP6_g:N}
`7+j0kV)
U>S`k6
public Utility() "R9Yb,tIN
{ D);'pKl
m-V02's
.5> 20\b2
} Nf9fb?
y69J%/c ra
//线程睡眠 P20|RvE
public static void sleep(int nSecond) k_GP>b\"k
{ YCy22@C
try{ (0Naf
Thread.sleep(nSecond); ?Qqd "=k4
} R^MiP|?ZH
catch(Exception e) C+K=[
{ .G>t72DpU
e.printStackTrace (); T~gW3J
} VY+>=!
} !asqr1/
zzZg$9PT[
//日志 wH"kk4^
public static void log(String sMsg) XTqm]
{ kGN||h
System.err.println(sMsg); pKJK9@Ad
} LD(C\
V/"}ku
/&Jv,[2kV
public static void log(int sMsg) z,*:x4}F
{ ?M6ag_h3
System.err.println(sMsg); ujgLJ77
} qJ8-9^E,L
} oP,9#FC|(
t7F.[uWD
!0 Q8iW:
/* xi'<y
**TestMethod.java h ?#@~
*/ jB@4b'y
package NetFox; !rTmR@e$/
(:\LWJX0=
(paf2F`~#
public class TestMethod { S7n"3.k
X)uDSI~
m-1?\bs
public TestMethod() _MYx%Z
{ ///xx/weblogic60b2_win.exe ;?IT)sNY
try{ `Y3(~~YGn
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); }qC SS<a
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); xRDiRj
SiteFileFetch fileFetch = new SiteFileFetch(bean); &K:' #[3V
fileFetch.start(); $W!]fcZlB
} A%ywj'|z
catch(Exception e){e.printStackTrace ();} *,#q'!Hq
IftxSaP
+T_ p8W+j
} "dN< i
!Qu PG/=X
`?o=*OS7Y
public static void main(String[] args) H`<?<ak6'M
{ 73DlRt *
new TestMethod(); E`p'L!z
} f =_^>>.
} a&/HSf_G
点击下载更多相关资料