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)); +!.^zp21
} F@B]et7
for(int i=0;i<nEndPos.length-1;i++) ?+}_1x`
{ 'AS|ZRr/
nEndPos = nStartPos[i+1]; b2&0Hx
} vnZC,J `
nEndPos[nEndPos.length-1] = nFileLength; E#N|wq
} ZX./P0
} `&ckZiq
]|PiF+
_^%,x
//启动子线程 (M.&^w;`,
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; N64dO[op
for(int i=0;i<nStartPos.length;i++) 3m!X/u
{ VQ9/Gxdeo
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ) ahA[
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), Fyatd
nStartPos,nEndPos,i); );&:9[b_
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); H%Q7D-
fileSplitterFetch.start(); ;u46Z
} l?n\i]'
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), JO6)-U$7UG
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); |imM#wF
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", hy"\RW
nEndPos = " + nFileLength); 9Y_HyOZ*GX
// fileSplitterFetch[nPos.length-1].start(); fSvM(3Y<Qh
>V8-i`
)cMh0SGcM1
//等待子线程结束 -**g~ty)
//int count = 0; LIF7/$,0
//是否结束while循环 )W _v:?A9
boolean breakWhile = false; 68C%B9.b'
|"CZT#
ud@%5d
while(!bStop) <&g,Nc'5C
{ PmEsN&YP]
write_nPos(); 3kp+<$
Utility.sleep(500); 6) [H?Q
breakWhile = true; XrGglBIV
V#gK$uv
gu.}M:u
for(int i=0;i<nStartPos.length;i++) v\%HPMlh
{ B!L{
if(!fileSplitterFetch.bDownOver) rlSeu5X6
{ x@;m8z0
breakWhile = false; 4yr'W8X_
break; yZU6xY
} 6HWE~`ok6
} =ncVnW{
if(breakWhile) i#Bf"W{F
break; `%9 uE(
ShP^A"Do
u.m[u)HQ
//count++; Zaf:fsj>
//if(count>4) jZkcBIK2
// siteStop(); FxWSV|Z
} ?_9
,CcV/K
>7T'OC
System.err.println("文件下载结束！"); h_3E)jc
} fW1CFRHH
catch(Exception e){e.printStackTrace ();} ! Y~FLA_
} K)|G0n*qS
U@)eTHv}6
i^Y+?Sx
//获得文件长度 CXx*_@}MU
public long getFileSize() A>;bHf@
{ :g=qz~2Xk
int nFileLength = -1; umH40rX+
try{ MKD1V8i
URL url = new URL(siteInfoBean.getSSiteURL()); t: ;Pj9
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); Y0dEH^I
httpConnection.setRequestProperty("User-Agent","NetFox"); x,@B(9No
Zbt.t]N
'9Xu p
int responseCode=httpConnection.getResponseCode(); $$;M^WV^?.
if(responseCode>=400) s.QwSbw-g
{ d_E/8R_$L
processErrorCode(responseCode); rCbDu&k]
return -2; //-2 represent access is error SaAFz&WRl
} Q}K"24`=
s %``H`
M@H;pJ+B
String sHeader; 4ber!rJM
'ud{m[|
x$.^"l-vX
for(int i=1;;i++) L;NvcUFn
{ U!?_W=?
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); dI@(<R
//Utility.log(in.readLine()); {14fA)`%
sHeader=httpConnection.getHeaderFieldKey(i); qJa H,
if(sHeader!=null) { VfXsI
{ r|fL&dtr
if(sHeader.equals("Content-Length")) Ls$D$/:q?
{ _~J {wM
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); "R1NG?;q
break; #64-~NVL_
} (pCrmyB
} FQ7T'G![
else < #}5IQ5`Z
break; ~IfJwBn-i
} tGh~!|P
} Ms5ap<q#
catch(IOException e){e.printStackTrace ();} HIR~"It$
catch(Exception e){e.printStackTrace ();} bz2ztH9 n
i$:*Pb3mV
;!mzyb*
Utility.log(nFileLength); L:pYn_
qYjce]c
2W96Zju\
return nFileLength; HV!m8k=6
} JPc+rfF
$%CF8\0
mAj?>;R2$2
//保存下载信息（文件指针位置） 3G)#5Lf<
private void write_nPos() Yz/md1T$
{ jrlVvzZ
try{ ~Ei$nV
output = new DataOutputStream(new FileOutputStream(tmpFile)); RK'\C\gMDu
output.writeInt(nStartPos.length); GmeQ`;9,
for(int i=0;i<nStartPos.length;i++) hz;G$cuEE
{ h-#6av:
// output.writeLong(nPos); Ic"ybj`
output.writeLong(fileSplitterFetch.nStartPos); Pw7]r<Q
output.writeLong(fileSplitterFetch.nEndPos); u<6<iD3y
} J!v3i*j\
output.close(); iwZPpl";
} F3v!AvA|
catch(IOException e){e.printStackTrace ();} x=hiQ>BIO0
catch(Exception e){e.printStackTrace ();} pMx*F@&nU
} I {S;L
0[NZ>7wqMZ
M=.n7RY-
//读取保存的下载信息（文件指针位置） <CYd+! (
private void read_nPos() j^j1
{ \:# L)
try{ fo*2:?K&
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); H1pO!>M
int nCount = input.readInt(); /yDz/>ID\
nStartPos = new long[nCount]; cz#rb*b
nEndPos = new long[nCount]; 6y%qVx#!
for(int i=0;i<nStartPos.length;i++) c)TPM/>(p
{ *v jmy/3
nStartPos = input.readLong(); "/*\1v9
nEndPos = input.readLong(); N ,'GN[s
} B4c]}r+
input.close(); -LoZs ru
} 8`q:Gz=M\
catch(IOException e){e.printStackTrace ();} ]_mb7X>
catch(Exception e){e.printStackTrace ();} =r?hgGWe
} |C;=-|
k$z_:X
(Y.k8";)`
private void processErrorCode(int nErrorCode) G\/zkrxmv
{ Zw 26
System.err.println("Error Code : " + nErrorCode); _JzEGpeG
} b@gc{R}7
V%7WUq
knu,"<
//停止文件下载 ?yrX)3hyH
public void siteStop() vsCCB}7\
{ qOIyub
bStop = true; 1y4|{7bb
for(int i=0;i<nStartPos.length;i++) }WC[$Y_@
fileSplitterFetch.splitterStop(); nMq,F#`3N
KVoS C@w
!=*g@mgF
} sQUM~HD\a
} ="1Ind@w!
//负责部分文件的抓取 MnsJEvn/
**FileSplitterFetch.java 0rQMLx
*/ E<{R.r
package NetFox; <.x{|p
Thp[+KP>
p,5i)nEFj
import java.io.*; Go`vfm"S
import java.net.*; e8>})
1E[J%Rh\l
,uSMQS-O'4
public class FileSplitterFetch extends Thread { oA7tEu
}Sm(]y
lK?uXr7^
String sURL; //File URL LiC*@W
long nStartPos; //File Snippet Start Position pz!Zs."f)
long nEndPos; //File Snippet End Position 2RVN\?s:
int nThreadID; //Thread's ID 7X`g,b!
boolean bDownOver = false; //Downing is over 0#7>o^2
boolean bStop = false; //Stop identical n*R])=F@c
FileAccessI fileAccessI = null; //File Access interface du $:jN\}
"(3[+W{|
Q,,e+exbb5
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException i^/T
{ J|W<;
this.sURL = sURL; 1jmjg~W
this.nStartPos = nStart; JK7G/]j+Ez
this.nEndPos = nEnd; A9KET$i@v
nThreadID = id; P>y@kPi
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :(E@Gf
} 5N#aXG^9
A]_7}<<N
|%BOZT
public void run() uP`Z12&
{ `[y^ :mj
while(nStartPos < nEndPos && !bStop) NJ%P/\ C
{ +C^nO=[E
_>o:R$ %}
l] K3Y\#bP
try{ {X!r8i
URL url = new URL(sURL); vz@A;t
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); 3<e=g)F
httpConnection.setRequestProperty("User-Agent","NetFox"); Yj<a" Gr4[
String sProperty = "bytes="+nStartPos+"-"; 7m47rJyW4
httpConnection.setRequestProperty("RANGE",sProperty); bt@< ut\
Utility.log(sProperty); vOH4#
XnH05LQ
3p$?,0ELH
InputStream input = httpConnection.getInputStream(); i7CX65&b
//logResponseHead(httpConnection); 0.Q Ujw
%HhBt5w
,5P0S0*{
byte[] b = new byte[1024]; +N]J5Ve-`t
int nRead; +WZX.D
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) k`cfG\;r
{ ^L,K& Jd
nStartPos += fileAccessI.write(b,0,nRead); =bAx,,D#
//if(nThreadID == 1) ]"pVj6O
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); +X\FBvP&
} dUD[e,?
WSPI|#Xr%
s2a{>II6
Utility.log("Thread " + nThreadID + " is over!"); {Ea b j
bDownOver = true; xf'V{9*
//nPos = fileAccessI.write (b,0,nRead); "-E\[@/
} "6("9"
catch(Exception e){e.printStackTrace ();} `{gHA+B
} nd`1m[7MNu
} FBG4pb9=~
K$z2YJ%
DVO.FTV^`
//打印回应的头信息 j\ZXG=j
public void logResponseHead(HttpURLConnection con) b3P+H r
{ Yz9owe8}[
for(int i=1;;i++) !@5 9)
{ x o;QCOH
String header=con.getHeaderFieldKey(i); ;t)3F
if(header!=null) qfX6TV5J}!
//responseHeaders.put(header,httpConnection.getHeaderField(header)); 44J]I\+
Utility.log(header+" : "+con.getHeaderField(header)); Mg+2. 8%
else M.JA.I@XC
break; `T1
} g%aYDl
} W PC]%:L"
.zf~.R;>
gZVc 5u<
public void splitterStop() &L3M]
{ "6A ` q\
bStop = true; {aZ0;
} RCJ|P~*
IM*y|UHt
g/4[N{Xf
} (xycJ`N
?C]vS_jAh
6dHOf,zjm
/* z,RhYm
**FileAccess.java k``_EiV4t
*//文件访问(定位，写) pt?bWyKG
package NetFox; R- X5K-
import java.io.*; HH`'*$]7
-+-?w|}qV
rDtY[
public class FileAccessI implements Serializable{ \Zk;ikEY
cUk7i`M;6
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 `Uq#W+r,
RandomAccessFile oSavedFile; aNsBcov3O
long nPos; 7lTC{7C57
gE-tjoJ
eNh39er
public FileAccessI() throws IOException KV91)U
{ \eTwXe]Pv
this("",0); G+9,,`2
} 0mp/Le5
_!#@@O0p/h
'JtBZFq
public FileAccessI(String sName,long nPos) throws IOException P-[-pi@
{ #I.+aV+2oQ
oSavedFile = new RandomAccessFile(sName,"rw"); u$z`
this.nPos = nPos; &md`$a/
oSavedFile.seek(nPos); 3qgS&js 7
} ME$[=?7XX
Xc++b|k
#&+{mCjs
public synchronized int write(byte[] b,int nStart,int nLen) T}Tp$.gB
{ yNBQGSH
int n = -1; i%iL[id:w
try{ e}voV0y\v:
oSavedFile.write(b,nStart,nLen); xa'*P=<)C'
n = nLen; F-QzrquS
} 8qoMo7-f
catch(IOException e) Gf6p'(\zun
{ E*&vy
e.printStackTrace (); Ha#=(9.
} Ng&%o
ejKucEgD
F~ty!(c
return n; 4(n-_BS
} eSn+B;
1y&\5kB
@3i\%R)n;
} bG"~"ipn%
+.8 \p5
>tS'Q`R
/* d7^}tM
**SiteInfoBean.java b#c:u2
*/ &N9 a<w8+
package NetFox; Yu/ID!`Z
krxo"WgD
u2I*-K
public class SiteInfoBean { r+!YIk
\<h0Q,e
Z3e| UAif
private String sSiteURL; //Site's URL /V8#[9K
private String sFilePath; //Saved File's Path yqs4[C
private String sFileName; //Saved File's Name C.:<-xo
private int nSplitter; //Count of Splited Downloading File u]wZQl#-
.8g)av+
~%F9%=
public SiteInfoBean() !.$I["/=
{//nSplitter的缺省值为5 9)yJ: N#F
//default value of nSplitter is 5 .~db4d]
this("","","",5); KM0ru
} 'c&Ed
T.F!+
QhFVxCA
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) "9uKtQS0o
{ 3yme1Mb
sSiteURL= sURL; yF:1( 4
sFilePath = sPath; 0JS?;fk
sFileName = sName; @ y.?:7I
this.nSplitter = nSpiltter; >{]%F*p4
G5_=H,Vmd
g'f@H-KCD
} tIi&;tw]
BR_1MG'{)$
Z#jZRNU%ox
public String getSSiteURL() pQ">UL*
{ iU918!!N
return sSiteURL; LP^$AAy
} H'5)UX@LP
uCvj!
"!P3R1;%
public void setSSiteURL(String value) ~NgA
{ b6M[q_
sSiteURL = value; tFn)aa~L
} n80?N}
JG.y,<xW
)m+W j
public String getSFilePath() F;EwQjTF
{ P:S.~Jq
return sFilePath; uc{Ihw
} g/_5unI}u
~At7 +F[
XW H5d-
public void setSFilePath(String value) QZwNw;$k*
{ hag$GX'2k
sFilePath = value; c]-<vkpV
} Gu,wF(x7A
o[4}h:> dq
l4YbKnp]
public String getSFileName() c]<5zyl"j1
{ 0o4XUW
return sFileName; k'Hs}zeNn
} &B;~
p>N(Typ0b
*R,5h2;
public void setSFileName(String value) nPtuTySG
{ E~T-=ocKE
sFileName = value; FGJ1dBLr
} 0auYG><=
FUzzB94a
By,eETU]
public int getNSplitter() b_krk\e@S
{ aKDKmHd
return nSplitter; ;1=1:S8
} <=&`ZH
e"cXun4nS=
T{^rt3a
public void setNSplitter(int nCount) ]0OR_'?,
{ 2'Uu:Y^
nSplitter = nCount; J{<X7uB
} Hio0HL-
} S+6.ZZ9c
,THw"bm
{uFO/
/* Qljpx?E
**Utility.java V &T~zh1
*/ MJ)RvNF
package NetFox; D)P._?
3M`M
Lb-OsKU
public class Utility { >|=ts
H41?/U,{
ty!`T+3
public Utility() Qel9G($=
{ hZ,_6mNg
I 34>X`[o
a-tmq]]E
} @1j
QIEJ6`
//线程睡眠 #X$\&,Yn"
public static void sleep(int nSecond) W@IQ^ }E
{ ,qwuLBW
try{ Dy&i&5E.-l
Thread.sleep(nSecond); =svN#q5s
} q<<v,ihh
catch(Exception e) wJqMa9|
{ o/)h"i0P
e.printStackTrace (); JR|ck=tq
} 1&OW4_
} q i;1L Kc
XT*sGM
//日志 v1JzP#
public static void log(String sMsg) ~ Iuf}D;
{ djZqc5t
System.err.println(sMsg); S hWJ72c
} 29b9`NXt
e9tjw[+A
WU` rh^
public static void log(int sMsg) cjY-y-vO
{ 6MW{,N
System.err.println(sMsg); P+sW[:
} 3?yg\
} (CL%>5V
l'qg8
D_7,m%Z:
/* T-L||yE,h
**TestMethod.java vr l-$ii
*/ u=sp`%?
package NetFox; l)\! .X
Fm 2AEs\
+sA2WK]
public class TestMethod { |df Pki{
xo&_bMO
mJnIwdW*
public TestMethod() BxmWIItz
{ ///xx/weblogic60b2_win.exe 3d]S!=4H"
try{ J8(lIk:e
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); &z3o7rif$
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); J@'wf8Ub
SiteFileFetch fileFetch = new SiteFileFetch(bean); "S]TP$O D
fileFetch.start(); jr."I+
} /6*42[r
catch(Exception e){e.printStackTrace ();} +'a^f5
!pW0qX\1n
T^KKy0ZGM
} }0z)5c
SH$PwJU
~mxO7cy5Cg
public static void main(String[] args) 7}>EJ
{ ki!0^t:9
new TestMethod(); t*u:hex
} +6\Zj)
} ~!L}yw
点击下载更多相关资料