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)); h[I~D`q)v
} *S=zJyAO
for(int i=0;i<nEndPos.length-1;i++) v6`TbIq%
{ #&ZwQw
nEndPos = nStartPos[i+1]; 2';f8JLY
} 0'4V*Y
nEndPos[nEndPos.length-1] = nFileLength; fI1,L"
} @`Foy
} ]-G10p}Ph-
Fb9!x/$tGV
7!"OF
//启动子线程 q\a'pp9d
fileSplitterFetch = new FileSplitterFetch[nStartPos.length]; 6l-V%3-
for(int i=0;i<nStartPos.length;i++) *T{P^q.s~[
{ o$+"{3svw?
fileSplitterFetch = new FileSplitterFetch(siteInfoBean.getSSiteURL(), x*2'I
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(), !/Wp0E'A
nStartPos,nEndPos,i); or{X{_X7
Utility.log("Thread " + i + " , nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); %>Y86>mVz
fileSplitterFetch.start(); ]S#m o
} beCTOmC
// fileSplitterFetch[nPos.length-1] = new FileSplitterFetch(siteInfoBean.getSSiteURL(), ~]&,v|g&
siteInfoBean.getSFilePath() + File.separator + siteInfoBean.getSFileName(),nPos[nPos.length-1],nFileLength,nPos.length-1); l d4#jV ei
// Utility.log("Thread " + (nPos.length-1) + " , nStartPos = " + nPos[nPos.length-1] + ", -<Zs7(
nEndPos = " + nFileLength); S8$kxQg
// fileSplitterFetch[nPos.length-1].start(); p?,:
R#UcwX}o
fd} Ul
//等待子线程结束 yDW$v/j.|
//int count = 0; ^+20e3 ~Y
//是否结束while循环 {(MC]]'?
boolean breakWhile = false; _.y0QkwV
4tv}V:EO
vPA {)l\K
while(!bStop) c3$h-M(jVJ
{ =UW! 7OzC
write_nPos(); uNSbAw3
Utility.sleep(500); dJ}E,rW}
breakWhile = true; 4PzCm k
DoA+Bwq@
9dFSppM
for(int i=0;i<nStartPos.length;i++) /?wH1 ,
{ u!VAAX
if(!fileSplitterFetch.bDownOver) =Vm"2g,aA
{ T2^0Q9E?
breakWhile = false; ZW0gd7Wh
break; 43 h0i-%1
} xVn"xk
} ,AO]4Ec
if(breakWhile) 42wa9UL<Ka
break; RiX~YLeM
u79,+H@ep
ZfYva(zP{Q
//count++; )|?s!rw +
//if(count>4) *6trK`tx^
// siteStop(); /X_g[*]?
} q`8M9-~
H=j&uv8
DL0i
System.err.println("文件下载结束！"); J<4egk4
} oSOO5dk:z
catch(Exception e){e.printStackTrace ();} NY`$D}Bi
} ,>rr|O
&>m# "A\^
<s7OY`(8
//获得文件长度 wtY*{m2
public long getFileSize() "=S< xT+
{ = UT^5cl(
int nFileLength = -1; XH?}0D(
try{ ,c;u]
URL url = new URL(siteInfoBean.getSSiteURL()); :DlgNR`bq
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); oS/cS)N20
httpConnection.setRequestProperty("User-Agent","NetFox"); N=QeeAI}}m
l12_&o"C~
y(!YN7_A
int responseCode=httpConnection.getResponseCode(); P~5[.6gW
if(responseCode>=400) Uczb"k5
{ @1w9!\7Vt
processErrorCode(responseCode); Gw/imXL
return -2; //-2 represent access is error !6UtwCVR
} 5g{F-
:bhpYEUMx
^K#PcPF-j
String sHeader; t'@qb~sf
!u0qF!/W
VQQtxHTC3
for(int i=1;;i++) $]Vvu{
{ 5zqlK-$
//DataInputStream in = new DataInputStream(httpConnection.getInputStream ()); ;%j1'VI
//Utility.log(in.readLine()); _rz*7-ks=
sHeader=httpConnection.getHeaderFieldKey(i); ]}~[2k.
if(sHeader!=null) El}."}l&
{ =D2jJk?AX
if(sHeader.equals("Content-Length")) l<]@5"wN
{ 9,4Lb]
nFileLength = Integer.parseInt(httpConnection.getHeaderField(sHeader)); JIl<4 %A
break; *hP9d;-Ar
} %$)[qa3
} c<`Z[EY(t
else -Tw96 dv
break; #Tjv(O[&
} sMq*X^z )?
} rl0sN5n
catch(IOException e){e.printStackTrace ();} ~e,D`Lv
catch(Exception e){e.printStackTrace ();} ){PL6|5x
me+F0:L
y3]7^+k
Utility.log(nFileLength); 43"`gF]
V?a+u7*U&
X_}2xo|T
return nFileLength; UKBVCAK
} OKo39 A\fu
[q/tKdo@
\Qh{uk[
//保存下载信息（文件指针位置） f:_\S
private void write_nPos() {g:I5 A#
{ B}%B4&Ij
try{ rHir> p
output = new DataOutputStream(new FileOutputStream(tmpFile)); iG\]
output.writeInt(nStartPos.length); m@r+M"!R
for(int i=0;i<nStartPos.length;i++) Jzg>Y?jN R
{ \M H\!
// output.writeLong(nPos); N6"b OxJ(
output.writeLong(fileSplitterFetch.nStartPos); f xWW"B*A
output.writeLong(fileSplitterFetch.nEndPos); "pDwN$c
} 'Y ZYRFWXM
output.close(); FY^[?lj
} WW'8&:x
catch(IOException e){e.printStackTrace ();} k}5Sz
catch(Exception e){e.printStackTrace ();} ]"jJgO^
} r+}5;fQJ
8b0!eB#_Ee
L"w% ew
//读取保存的下载信息（文件指针位置） L8&$o2+07r
private void read_nPos() V'XmMn)!
{ T+OQa+E@P
try{ \,-t]$9
DataInputStream input = new DataInputStream(new FileInputStream(tmpFile)); 'w?*4H
int nCount = input.readInt(); _%M5 T
nStartPos = new long[nCount]; 9!u=q5+E
nEndPos = new long[nCount]; |a(%a43fC
for(int i=0;i<nStartPos.length;i++) wF +9Iu
{ om`x"x&6
nStartPos = input.readLong(); Ag3[Nu1
nEndPos = input.readLong(); JMMT886
} vPm&0,R*y:
input.close(); c~@Z
} s~@4
catch(IOException e){e.printStackTrace ();} %Ts6M,Fpp
catch(Exception e){e.printStackTrace ();} y~.k-b<{[
} 6;02_C]\o
-R^OYgF
u~|D;e
private void processErrorCode(int nErrorCode) x<m{B@3T
{ t:DZow
System.err.println("Error Code : " + nErrorCode); p[Pa(a,B7
} {bxTODt@
}klET
=l %
//停止文件下载 As$:V<Z
public void siteStop() PdUlwT?8C
{ uQwKnD?F+e
bStop = true; 0Q81$% @<
for(int i=0;i<nStartPos.length;i++) XYJ7k7zc+Y
fileSplitterFetch.splitterStop(); Y:GSjq
VJK?"mX
^xWu7q
} }@kD&2
} aZ[ aZU
//负责部分文件的抓取 1:7 uS.
**FileSplitterFetch.java +d7sy0
*/ PSOW}Y|q
package NetFox; SLzxFuV
8JOfx
tE i-0J
import java.io.*; E?{{z4
import java.net.*; -^C't_Q o
6TN!63{Cz
OLThi[Yn
public class FileSplitterFetch extends Thread { |v,5s=}7
N7S?m@
5pJ)OX
String sURL; //File URL n"[VM=YGI
long nStartPos; //File Snippet Start Position ra="4T$va
long nEndPos; //File Snippet End Position WE_jT1^/
int nThreadID; //Thread's ID Q9-o$4#R[
boolean bDownOver = false; //Downing is over 0q|.]:][Eo
boolean bStop = false; //Stop identical Fap@cW3?8
FileAccessI fileAccessI = null; //File Access interface :xn/9y+s
>k:BG{$Kae
IO,ddVO
public FileSplitterFetch(String sURL,String sName,long nStart,long nEnd,int id) throws IOException YL(7l|^!
{ 85>WK+=
this.sURL = sURL; i%1ny`Q
this.nStartPos = nStart; aq'dC=y
this.nEndPos = nEnd; /%El0X
nThreadID = id; gk"0r\Eq
fileAccessI = new FileAccessI(sName,nStartPos);//定位 :6~DOvY
} O}4(v#
7MRu=Z.-b
Gi7jgv{{
public void run() 9ghZLQ
{ ttazY#
while(nStartPos < nEndPos && !bStop) ~]+-<O^U~
{ }LXS!Ff:
3=6`'PKRQ
I) mP?
try{ N|Cx";,|FZ
URL url = new URL(sURL); <AZ21"oR/
HttpURLConnection httpConnection = (HttpURLConnection)url.openConnection (); G#V}9l8Q
httpConnection.setRequestProperty("User-Agent","NetFox"); XkB^.[B
String sProperty = "bytes="+nStartPos+"-"; W/z\j/Rgc
httpConnection.setRequestProperty("RANGE",sProperty); ?\_N*NEtK
Utility.log(sProperty); 'ZyHp=RN)
q4].C|7
tTWeOAF
InputStream input = httpConnection.getInputStream(); ya!RiHj
//logResponseHead(httpConnection); %Pr PCT
U}H2!et&,)
mI55vNyer
byte[] b = new byte[1024]; ?{bF3Mz=
int nRead; ( K5w0
while((nRead=input.read(b,0,1024)) > 0 && nStartPos < nEndPos && !bStop) I\NiA>c
{ Q.5C$I
nStartPos += fileAccessI.write(b,0,nRead); gv&%2e}_
//if(nThreadID == 1) nZ;h&N-_-
// Utility.log("nStartPos = " + nStartPos + ", nEndPos = " + nEndPos); pEUbP,3M:
} ]<9=%m
VieX5
O>zPWVwa
Utility.log("Thread " + nThreadID + " is over!"); I y?_2m
bDownOver = true; y[U/5! `zV
//nPos = fileAccessI.write (b,0,nRead); h,|49~^@"
} s%tPGjMq
catch(Exception e){e.printStackTrace ();} 8"!Z^_y)
} l2v4SvbX
} mL\j^q,Y
adHZX
<+MNv#1:w
//打印回应的头信息 |aH;@V
public void logResponseHead(HttpURLConnection con) j@4 yRl ^
{ ]Y#$!fIx
for(int i=1;;i++) Ri$wt.b
{ Qo*,2B9R L
String header=con.getHeaderFieldKey(i); BMw_F)hTO
if(header!=null) sE*A,z?
//responseHeaders.put(header,httpConnection.getHeaderField(header)); ]LFY2w<
Utility.log(header+" : "+con.getHeaderField(header)); V^O dTM
else owClnp9K
break; _dCsYI%
} /*5t@_0fe
} #;Yn8'a~
]~my<3j}or
gu+c7qe
public void splitterStop() }-3| v<d
{ mQRQ2SN6
bStop = true; C-@
} 't2dP,u<-
e:9CD-
k+xj 2)d7
} a6K1-SR^6)
"=l<%em
P;%4Imq3
/* w(w%~;\kLP
**FileAccess.java d4"KM+EP?
*//文件访问(定位，写) .@0i,7S
package NetFox; D]+0X8@kH7
import java.io.*; $gi{)'z
v#iKa+tx
xrbDqA.b
public class FileAccessI implements Serializable{ ;Qpp[V`
AXBv']Y
//RandomAccessFile类用于在任意一个文件的特定位置上读/写字节 P0m;AqS#R
RandomAccessFile oSavedFile; 3nfw:.
long nPos; 5pNbO[
PP+{zy9Sb
qaBjV6loy
public FileAccessI() throws IOException &KfRZ`9H
{ ()=u#y
this("",0); 0sjw`<ic
} }s;W{Q
xNG'UbU
".&x`C
public FileAccessI(String sName,long nPos) throws IOException vkE[Ur>
{ 3zJbb3e
oSavedFile = new RandomAccessFile(sName,"rw"); ZN)a}\]
this.nPos = nPos; %G9:M;|'
oSavedFile.seek(nPos); O=os ,'"
} vF, !8e'v
?#@JH
D:Zpls.
public synchronized int write(byte[] b,int nStart,int nLen) TGxspmY6
{ ^H'zS3S
int n = -1; Ro+/=*ql~
try{ |]7z
oSavedFile.write(b,nStart,nLen); sY?pp '}a
n = nLen; owA3>E5t&
} ZoJ:4uo N`
catch(IOException e) cnAwoTt4
{ 'U<-w$!f+^
e.printStackTrace (); {;4AdZk
} ^FSUK
]JQk,<l5E
Zf<M14iM
return n; wAE,mw
} m ys5B}
tN|sHgs
Y$3H$F.+
} mq$mB1$3u
CFJ F}aW
q|J3]F !n
/* \XR%pC
**SiteInfoBean.java 4kO[|~#
*/ oD,f5Ci-
package NetFox; A3%s5`vNvH
>'#G$f
3=9yR**
public class SiteInfoBean { aK'`yuN
]E90q/s@c
X&._<2
private String sSiteURL; //Site's URL LPbZ.
private String sFilePath; //Saved File's Path (j-[m\wF
private String sFileName; //Saved File's Name PezUG{q(
private int nSplitter; //Count of Splited Downloading File Yck(Fl
w5"C<5^
@YyTXg{ZK
public SiteInfoBean() gO-C[j/
{//nSplitter的缺省值为5 Z(AI]wk3<
//default value of nSplitter is 5 11}fPWK
this("","","",5); nGA'\+zjL
} c@:L7#8
<:yB4t3H+q
ShanwaCDqv
public SiteInfoBean(String sURL,String sPath,String sName,int nSpiltter) nf!RB-orF
{ Y>-|`2Z
sSiteURL= sURL; po_||NIY
sFilePath = sPath; c8mcJAc
sFileName = sName; ywlN4=
this.nSplitter = nSpiltter; 7G}vQO
0N.tPF}
Xr~6_N{J
} hd1H
.E|Hk,c9
l)E \mo 8
public String getSSiteURL() bL5z%bV
{ Sv.z9@S
return sSiteURL; :bMCmY
} "iE9X.6NMu
-bSe=09;S|
06 gE;iT
public void setSSiteURL(String value) 5,>1rd<B
{ 'Omi3LXfDT
sSiteURL = value; ^\ &:'$f+8
} W5*%n]s~
kNfqdCF{P
W?{:HV
public String getSFilePath() j[YzBXd V
{ Kg&{ ?&
return sFilePath; y|b|_eE?{
} B+|E|8"
p8y_uNQE
1QM*oj:
public void setSFilePath(String value) J=>?D@K
{ eSXt"t
sFilePath = value; I,Q"<?&
} >L/Rf8j&
!o &+
k%#`{#ni
public String getSFileName() VtF^; f
{ xbrxh-gV
return sFileName; Ay<'Z6`
} m` cw:
dz.]5R
iC&=-$vu
public void setSFileName(String value) rKq/=Avv
{ 1&c>v3 $2
sFileName = value; 8Q^yh6z
} }[Uh4k8P
=nOV!!
:7p0JGd
public int getNSplitter() TCp!4-~,
{ 49}yw3-
return nSplitter; "s2?cQv{#
} i^sK+v
4vTO #F
k|-`d
public void setNSplitter(int nCount) c\UVMyE
{ }gyJaMA
nSplitter = nCount; @Fqh]1t
} (6z^m?t?
} exV6&bdu
wXDF7tJh
t$r^'ZN
/* +V1EqC*
**Utility.java 8YraW|H
*/ n1o/-UY
package NetFox; &/R@cS6}'
C.s{&
@/yRE^c
public class Utility { (?xGlV`n
qf+jfc(Iby
%([$v6y
public Utility() OYC4iI
{ JU:!lyd
WKX5Dl
cO<]%L0
} 57IrD*{
\v]}
//线程睡眠 wRb%-s
public static void sleep(int nSecond) y&9S+
{ _)2.#L
try{ zc]F
Thread.sleep(nSecond); O/gok+K
} QL}5vSl
catch(Exception e) R B.j@*
{ #NNj#
e.printStackTrace (); >joGGT
} O;f^'N
} 4C[,S|J
fOJk+? c
//日志 +%X_+9bd
public static void log(String sMsg) !$AVlMnJ
{ KpC)A5u6
System.err.println(sMsg); ,oIZ5u{#,
} jd l1Q<Z
=nFT0];
nSsVONHfa
public static void log(int sMsg) s8}:8
{ M ^ZoBsZ
System.err.println(sMsg); f1=BBQY >
} xj{X#[q):
} "Na9Xea
O 4N_lr~
J><O 51
/* L;nRI.
**TestMethod.java 52m^jT Sx
*/ ?Li^XONz
package NetFox; a%tm[Re
T =3te|fv
jp8=>mk
public class TestMethod { m<8j' [+
Jl Q%+$
yr&oJYM
public TestMethod() YC&iH>jO3
{ ///xx/weblogic60b2_win.exe ~D@V@sX
try{ zA&0H
SiteInfoBean bean = new SiteInfoBean("http://localhost/xx/weblogic60b2_win.exe","L:\\temp","weblogic60b2_win.exe",5); ,M7sOp6}
//SiteInfoBean bean = new SiteInfoBean("http://localhost:8080/down.zip","L:\\temp","weblogic60b2_win.exe",5); f Otrn
SiteFileFetch fileFetch = new SiteFileFetch(bean); |C'w] QYm
fileFetch.start(); /2>-h-zBjw
} 7zr\AgV9
catch(Exception e){e.printStackTrace ();} U`FybP2R~
WeuV+}\b
`m3@mJ!>\
} -_uL;9r
2-llT
Ms1G&NYP
public static void main(String[] args) VT3Zo%Xx
{ Sx;zvc
new TestMethod(); &-<"HW
} wuzz Wq
} }K~JM1(26
点击下载更多相关资料